Auto Calculators

Turn a monthly payment budget into the car price you can afford, with down payment, trade-in and payoff, sales tax, fees and rebates — plus out-the-door cost, cash due at signing, price by loan term and an amortization schedule.

Estimate a monthly car lease payment with sales tax, fees, rebates, trade-in and mileage, see the amount due at signing and the total lease cost, or find the price that hits a target payment.

Compare the total cost of leasing a car against buying it with a loan over the same period.

See how a car loses value year by year, with a depreciation schedule and the total value lost.

Add up fuel, insurance, maintenance and payments to find what each mile of driving really costs.

Work out the fuel cost of one trip or of your regular driving per week, month or year — in MPG (US or UK), L/100 km, km/L or gallons per 100 miles — with fuel used, cost per mile or km, fill-ups and a side-by-side with another car.

Estimate what it costs to charge an electric car from your electricity rate, battery size and charge level.

Compare the yearly fuel cost of a gas car against an electric car and see the annual savings.

Convert a tire spec like 225/45R17 into overall diameter, sidewall height, circumference and revolutions per mile.

Find the axle gear ratio from ring and pinion teeth, plus the engine RPM at a given speed.

Calculate horsepower from torque and RPM with the classic hp = torque × RPM ÷ 5252 formula.

Calculate miles per gallon from miles driven and gallons used, plus cost per mile and yearly fuel cost.

Estimate how long it takes to charge an electric car from your battery size, charger power, start and target charge, and charging efficiency.

Estimate a car's 0-60 mph and 0-100 km/h time from weight and horsepower, with drivetrain, gearbox, tires, wet roads and magazine rollout, or find the horsepower needed for a target time. Includes times to 30-100 mph, quarter mile and traction limit.

Estimate quarter-mile and eighth-mile ET and trap speed from weight and horsepower, or work back to horsepower from a time slip — with Huntington, Fox and Hale formulas, wheel or crank power, driver weight and density altitude.

Calculate engine displacement in cc, litres and cubic inches from bore, stroke and cylinder count.

Calculate a displacement hull's theoretical hull speed in knots, mph and km/h from the waterline length.

Estimate what an electric-car road trip costs to charge, adjust for cold-weather range loss, and compare it to a gas car.

Check whether your overland build stays under the vehicle payload rating once passengers, tent, water, fuel, gear and mods are loaded.

See how a taller or shorter tire throws off your speedometer and odometer, with the true speed and the corrected readings.

Calculate an engine’s static compression ratio from bore, stroke, chamber volume, head gasket and deck clearance.

Convert torque and RPM into horsepower with the classic hp = torque × RPM ÷ 5252 formula.

Work out engine torque in lb-ft from horsepower and RPM using torque = hp × 5252 ÷ RPM.

See how tire pressure changes with temperature and find the adjusted psi for a new ambient temperature.

Estimate a car’s lease-end residual value and the depreciation you pay from MSRP, residual percent and term.

Estimate the maximum trailer weight you can safely tow from your GCWR, curb weight and payload.

Mix E85 and pump gas to hit a target ethanol percentage — for a fresh batch or a top-off of a partly full tank — or work out the ethanol content of a mix or a water test, with stoichiometric AFR, extra fuel flow, energy content and cost.

Estimate the horsepower gain from turbo or supercharger boost based on your naturally aspirated power and boost pressure.

Find engine RPM at a given speed from tire diameter, axle ratio and transmission gear ratio.

Convert an air-fuel ratio to lambda for gasoline, E85, diesel or methanol and see whether the mixture is rich or lean.

Size fuel injectors in cc/min and lb/hr from your horsepower target, injector count, BSFC and duty cycle.

Compare the annual fuel cost of a gas car against a diesel and see which is cheaper and by how much.

Turn your income, debts, down payment and trade-in into the car price you can afford, with sales tax and fees, a debt-to-income check, running costs and the 20/4/10 rule.

Project what your car will be worth after several years using a declining-balance depreciation rate — and see the loss year by year.

Add up depreciation, fuel, insurance, maintenance, fees and loan interest to see the true 5-year cost of owning a car.

Compare the true cost of leasing versus financing the same car over the same period — including the equity you keep when you buy.

See how extra monthly, yearly or one-time payments shorten your car loan and how much interest they save — or find the extra payment needed to be debt-free by a target date — with a full payoff schedule.

Compare your car’s trade-in offer with your loan payoff to find your equity, see how it changes the loan and payment on your next car, what trading in saves in sales tax, and when negative equity will turn positive.

Add up fuel, insurance, maintenance, depreciation and fees to find your true all-in cost to drive one mile.

Compare the annual fuel cost of an electric car to a gas car and see how much charging instead of filling up saves.

Multiply your business miles by the IRS standard mileage rate to find your reimbursement or deduction.

See how much you save each year by switching to a more fuel-efficient car — in dollars and gallons.

Estimate the sales tax on a car purchase, including a trade-in credit and dealer fees, to get your out-the-door price.

Add your car payment, insurance, fuel, maintenance and fees into a single monthly cost of driving — and see its share of your income.

Estimate the fuel cost of a road trip from the distance, your car’s MPG and the price of gas — and split it between passengers.

Find how far you can drive on a full tank from your fuel economy and tank size — plus a safe range that keeps a reserve.

Work out how many gallons a trip needs from the distance and your fuel economy — plus the cost and how many fill-ups it takes.

Calculate engine displacement from bore, stroke and cylinder count in mm or inches, solve for the bore or stroke a target size needs, and see bore/stroke ratio, overbore and stroker gains, piston speed and compression ratio.

Estimate engine horsepower from your quarter-mile trap speed and vehicle weight using Hale’s trap-speed formula.

Estimate a car’s 0-60 mph time from its horsepower and weight using a constant-power model with a real-world traction factor.

Find your differential final drive ratio from ring and pinion teeth, and the overall ratio in any gear.

Calculate vehicle speed from engine RPM, gear ratio, final drive and tire diameter — or find the RPM at a given cruise speed.

Compare two tire sizes side by side — overall diameter, circumference, sidewall height and the speedometer error from switching.

Convert wheel offset (ET) to backspacing and front spacing or back again, and compare a new wheel with your current one: how far the outer lip pokes out, how much inner clearance you lose, track width change, wheel spacers and tire width.

Calculate the number of chain links a motorcycle needs from the front and rear sprocket sizes, center distance and chain pitch.

Work out what oil changes cost per year, per mile and over several years, using a mileage interval or a time limit (whichever comes first). Enter a shop price or build it from quarts, oil price, filter and labor, then compare a longer synthetic interval and DIY.

Turn how far you drive, your car’s MPG and the pump price into a monthly, weekly and yearly fuel budget.

Combine fuel and per-mile maintenance to see what a year of driving really costs — and your true cost per mile.

A more efficient car costs more up front — see how many years of fuel savings it takes to pay back the price premium.

Add fuel, tolls and parking across your working year to see what driving to the job really costs each week and year.

Split a commute among riders and see how much each person saves on fuel every week, month and year.

Estimate your yearly vehicle registration cost from a value-based rate and flat fees, or with the 2026 formulas for California (VLF), Arizona (VLT), Colorado, Massachusetts, Minnesota and Nevada. Shows the value-based part you may deduct and a year-by-year projection as the car ages.

See exactly how price, tax, trade-in and your down payment split into cash up front versus the amount you finance — and the monthly payment.

Owe more than your car is worth? See how rolling that negative equity into a new loan inflates the balance, payment and interest, how long you stay underwater, and what paying the gap in cash or a shorter term would save.

Weigh an extended car warranty against likely repair bills to see whether it pays off — and the repair cost you’d need to break even.

Add up oil changes, detailing and routine service across a year to see your real monthly and yearly upkeep cost.

Turn the price of a tire set and its tread life into a true cost per mile — and compare cheap versus long-life tires fairly.

See how little time you actually save by driving faster on a trip — and weigh it against the extra risk and fuel.

Estimate an electric car’s driving range from its usable battery size and energy efficiency, and see the miles you get per kilowatt-hour.

Work out how long an EV takes to charge between two battery levels for any charger power, from a home outlet to a DC fast charger.

Turn an EV’s energy use per 100 miles and your electricity rate into a cost per mile, per 100 miles and MPGe.

See how long the fuel savings of a hybrid take to repay its higher purchase price, given your annual mileage and gas price.

Project whether you’ll exceed your car lease’s mileage allowance and what the excess-mileage charge will cost at turn-in.

Compare your loan balance to your car’s value to see the “gap” GAP insurance would cover if the vehicle were totaled.

See the total interest you’ll pay over the life of a car loan, plus the monthly payment and total repaid, for any rate and term.

Compare your current car loan with a refinance offer: new payment, monthly change, interest saved, net savings after fees, break-even month and a side-by-side term comparison.

Add sales tax, dealer fees and registration to a car’s price — after any trade-in — to find the true out-the-door cost.

Project a car’s value year by year using a steep first-year drop and a gentler decline after, with a full depreciation table.

Find what a fuel-system cleaner or additive costs per tank and per year based on how much one bottle treats and your fill-up habits.

Split a target volume of coolant or washer fluid into the right amounts of concentrate and water for the concentration you want.

Convert crank (brake) horsepower to wheel horsepower by subtracting drivetrain loss, and see how many horses the driveline eats.

Estimate a car’s quarter-mile elapsed time and trap speed from its horsepower and weight using proven drag-racing formulas.

Estimate a car’s aerodynamically-limited top speed from its horsepower, drag coefficient and frontal area.

Turn a tire size like 225/45R17, LT265/70R17 or 33x12.50R15 into overall diameter, width, sidewall, circumference and revolutions per mile or km — then compare a second size for diameter difference, speedometer error and similar-height sizes on other rims.

See how a change in tire diameter throws off your speedometer, and find your true speed after fitting taller or shorter tires.

Work out vehicle speed at a given RPM from your tire diameter, transmission gear ratio and final-drive (axle) ratio.

Estimate how far you can drive on the fuel left in the tank from your fuel economy, with a safety reserve you keep untouched.

Estimate diesel exhaust fluid (DEF) consumption from your mileage and fuel economy, and how far one DEF tank will last.

Estimate how much engine oil a change needs from engine size and type (gasoline, turbo, diesel or motorcycle) or from your manual’s figure, with the filter, a likely range, how many quarts or jugs to buy at the lowest price, and the cost per change and per year.

Find when your next tire rotation is due, how far until it, and how many rotations you’ll do per year from your driving.

Estimate the minimum cold cranking amps your battery needs from engine size, fuel type and how cold your winters get.

Check your trailer’s tongue weight against the recommended 10–15% of loaded weight to keep towing stable and safe.

Estimate how many gallons of automotive paint a respray needs from the body surface area, number of coats, coverage and spray-gun transfer efficiency.

Work out how many linear feet and square feet of vinyl a full or partial vehicle wrap needs, including a waste allowance for overlaps and mistakes.

Find out how many millilitres of ceramic coating and how many bottles a car needs from its surface area, the coating’s coverage rate and the number of layers.

Estimate the remaining life of your brake pads from their measured wear so far — how many more miles before they hit the minimum thickness.

Estimate how much life is left in a manual clutch from its expected lifespan, driving style and the miles already on it.

See when your timing belt is due and what it costs per mile and per year, from the service interval, your mileage and the parts-plus-labour quote.

Split your cooling system’s total capacity into concentrated antifreeze and water for a target coolant concentration — the classic 50/50 or a custom ratio.

Estimate how much refrigerant to add to a partially charged car air-conditioning system and how many cans it takes to top it back up.

Estimate how long a car battery of a given group size will run an accessory load — camping fridge, lights or audio — before it hits a safe depth of discharge.

Check whether your alternator keeps up with the electrical load at cruise and at idle, and see the amperage headroom or shortfall.

Convert a spark plug gap between millimetres, inches and thousandths, and see how far you need to open or close the gap to reach spec.

Turn a turbo or supercharger boost pressure into the engine’s effective compression ratio, so you can judge fuel octane and detonation risk.

Find the trailer tongue weight and its percentage of loaded trailer weight, and see whether your cargo sits far enough forward of the axle for stable towing.

Work out how much payload is left in your truck once passengers, cargo and the trailer’s tongue weight are subtracted from the door-jamb payload rating.

Estimate how many days until your RV black or grey tank fills up, based on tank size, number of people and daily usage — so you know when to dump.

Estimate the pin (kingpin) weight of a fifth-wheel or gooseneck trailer as a percentage of its loaded weight, and check it against the truck’s payload.

Check whether a boat trailer is rated for your rig by comparing its GVWR against the boat, motor, fuel, gear and the trailer’s own weight.

Find the safe ramp length and load angle for loading an ATV or UTV into a truck bed or trailer, and check it against the machine’s ground clearance.

See how much cargo your roof rack can carry after subtracting the crossbars and accessories from the lower of the rack and roof dynamic weight limits.

Calculate the usable cargo volume of a van in cubic feet and cubic metres from the interior length, width and height behind the seats.

Convert a box truck’s cargo box dimensions in feet and inches to total and usable cubic feet, and estimate how many standard moving boxes it holds.

Estimate the moving truck size you need in cubic feet from the number of rooms in your home, and see which common truck length fits the load.

Estimate the extra fuel and cost of towing on a trip by applying a fuel-economy penalty to your unloaded MPG over the trip distance.

Convert a tire’s load index to its maximum load in pounds and kilograms, and see the total load a full set of four can safely carry.

Compare the total cost of leasing versus buying a car over the same period, accounting for resale value.

Convert horsepower to torque (and back) at a given engine RPM.

Estimate the fuel cost of a road trip and split it between passengers.

Estimate what switching from a gas car to an EV saves: fuel versus home and public charging, per mile and per year, over the years you keep the car with price rises, plus maintenance, insurance, the price gap, payback year, break-even prices and CO₂.

Calculate vehicle speed from engine RPM, gear ratio, final drive and tire diameter.

Estimate a car’s 0–100 km/h acceleration time from its power and weight.

Check how much towing capacity you have left after your trailer and cargo, and whether you are within a safe margin.

Final-drive ratio from front and rear sprocket teeth, speed and rpm in every gear from tyre size and primary/gearbox ratios, how a sprocket change alters acceleration, cruising rpm and the speedometer, a sprocket-combination grid, and the chain length and axle shift for the new setup.

Estimate steer, drive and trailer axle weights for a tractor-trailer from cargo weight and its centre of gravity, compare against US federal limits (12,000 / 34,000 / 34,000 lb, 80,000 GVW) and find where to shift the load or slide the tandems.

Realistic truckload transit time from distance, average speed, loading and unloading time and current US FMCSA hours-of-service rules — 11-hour driving, 14-hour window, 30-minute break, 10-hour rest, 60/70-hour cycle with 34-hour restart, split-sleeper loading and adverse conditions — with a stop-by-stop schedule, solo vs team comparison and the earliest arrival date and time.

Decide whether collision and comprehensive insurance still pays on an older car: premium versus the car’s value minus the deductible, both versions of the 10% rule, break-even claim probability, expected value at your accident risk, comprehensive-only and higher-deductible options, and a year-by-year view of what banking the premium would build.

Convert wheel offset (ET) to backspacing and back for any wheel width, or compare a new wheel with the stock one: how far the tyre and rim move toward the strut and the fender, clearance left, the offset range that fits, spacer effect and track width change.

Find a wheel's bolt pattern from a tape measurement — the pitch circle diameter for 4-, 5-, 6- and 8-lug wheels from the distance between adjacent holes or, for 5-lug, from the centre of one hole to the far edge of the opposite hole — with mm ↔ inch conversion, common patterns (5×114.3, 5×120, 6×139.7) and the dual-pattern compatibility check.

See what larger tyres do to a truck or 4×4 — effective axle ratio, engine RPM at highway speed, speedometer and odometer error, the loss of torque at the wheels and the crawl ratio — and get the axle ratio that restores factory performance, with a table of common gear sets.

Calculate a 4×4's crawl ratio from first gear, transfer-case low range and axle ratio — plus the wheel speed at idle, the effect of tyre size, what an aftermarket low-range or axle gear would do, and the crawl-ratio targets for trail, rock crawling and overlanding with automatic vs manual transmissions.

Work out the octane of a mix of two fuels — how many litres or gallons of 93/98/100/race fuel to add to a tank of 87/91/95 to hit a target octane, the octane of what is already in the tank after a fill, E85 blends (with the ethanol percentage), and what an octane booster bottle really adds in points.

Mix pump gasoline and E85 to a target ethanol content (E20, E30, E50) by volume for a tank or a partial fill, correct for the real ethanol content of the E85 at the pump, and see the stoichiometric AFR, the extra fuel flow and injector duty the engine will need, and the energy-content and mpg penalty.

Correct dyno horsepower and torque for weather — the SAE J1349, STD (J607) and DIN 70020 correction factors from air temperature, barometric pressure and humidity — see corrected vs observed power, why the numbers differ between standards and shops, and the power your engine really makes on a hot or high-altitude day.

Size a recovery winch — the 1.5× gross-vehicle-weight rule, the pull actually needed for mud, sand or a slope from rolling-resistance and gradient factors, how a snatch block doubles the effective pull, and how the rated pull falls with each layer of rope on the drum.

Estimate a car or two-wheeler's on-road price from the ex-showroom price: state road tax (RTO) slabs for Maharashtra, Karnataka, Delhi, Tamil Nadu, Telangana, Uttar Pradesh, Gujarat, Kerala, West Bengal, Haryana and others, registration and HSRP charges, first-year comprehensive insurance, 1% TCS above ₹10 lakh, FASTag and handling, plus the EV concession and how a second car or diesel changes the tax.

Estimate highway tolls for a road trip in India from the distance on national highways and expressways, the vehicle class (car, LCV, bus, truck), the number of plazas, return-journey and monthly-pass discounts, whether the ₹3,000 FASTag annual pass (200 trips) beats pay-per-trip for your usage, the cash penalty for no FASTag, and toll as a share of the trip's fuel cost.

Compare what a car costs to run per kilometre in India on petrol, diesel, CNG and electricity at your local prices and mileage figures, the monthly and annual fuel bill for your usage, the payback period of a CNG kit or the EV price premium, the effect of CNG's reduced boot space and range, maintenance differences, and the break-even monthly kilometres for each choice.

Set RV, fifth-wheel and travel-trailer tyre pressures from the weight each axle actually carries at the scale: load per tyre with a safety margin, the pressure that carries it from the tyre's maximum load and pressure, the margin to the load rating, and why trailer tyres run at the sidewall maximum.

Work out how much an RV can actually carry: occupant and cargo carrying capacity from GVWR and unloaded weight, less full fresh water and propane, passengers and pets, then what is left for gear and food — with the common upgrades (batteries, solar, generator, bikes) that quietly eat the margin.

Add up a horse trailer's real loaded weight — trailer, horses, tack, hay, water and a living-quarters load — then check it against the trailer's GVWR, the tow vehicle's tow rating and payload with the tongue or pin weight, and see how much margin is left for a safe, legal haul.

How much 2-stroke oil to add to gasoline for 50:1, 40:1, 32:1, 25:1 or 100:1 premix — in mL per litre or fl oz per gallon, with a ready mixing table for chainsaws, trimmers, outboards and dirt bikes.

Find the real VLT of a tinted car window: factory glass × film (or two films) gives the combined visible light transmission, checked against your legal limit, with the darkest film you can legally add.

Convert engine hours to kilometres or miles for cars, trucks, police vehicles, boats and tractors: distance from average speed, idle time counted as wear-equivalent distance, and real average speed from the odometer.

Calculate mean and peak piston speed from stroke, rpm and rod length, in m/s and ft/min, rate it against street, performance and racing engines, and find the rpm for any piston-speed limit.

How many kilometres or miles are left on your tires? From new and current tread depth and distance driven, find your wear rate, remaining distance to the legal or wet-safety limit and how many years until replacement.

Calculate stopping sight distance (SSD) with the AASHTO Green Book formula — brake reaction distance plus braking distance — from design speed, reaction time, deceleration and grade, in metres or feet.

Estimate how fast a vehicle was going from the length of its skid marks with the accident-reconstruction formula S = √(30·d·f) — road surface drag factor, braking efficiency and grade, in km/h or mph.

Work out a safe following distance from your speed with the 3-second rule — in metres or feet and car lengths — with extra time for rain, snow or towing, and compare it with the stopping distance.

Calculate the lean angle a motorcycle needs for a corner from speed and turn radius — θ = atan(v² ÷ g·r) — plus lateral g, tyre grip needed and the top speed at your lean limit.

Find the maximum speed a car can take a curve from its radius, the road grip and the banking (superelevation) — v = √(g·r·(μ + e) ÷ (1 − μe)) — with the AASHTO highway formula and lateral g.

Convert electric car efficiency between kWh/100 km, kWh/100 mi, Wh/km, Wh/mi, km/kWh, mi/kWh and MPGe (33.7 kWh per gallon), plus the gasoline-equivalent L/100 km.

Estimate how much range an electric car loses in cold (or hot) weather from the outside temperature, average speed and heat pump or resistive heater — winter range, kWh/100 km and a range-by-temperature table.

Estimate an electric car battery's state of health and remaining range after any number of years, from charging habits and climate, using Geotab fleet data (about 1.5–3% capacity loss a year).

Calculate an engine's specific output — horsepower per litre, kW per litre and PS (CV) per litre — from power and displacement in L, cc or cubic inches, plus power and displacement per cylinder.

Calculate an engine's rod ratio (connecting-rod length ÷ stroke), maximum rod angle, piston position at 90° and the block deck height needed for a given rod, stroke and piston compression height.

Calculate a vehicle's turning radius and curb-to-curb turning circle from wheelbase and maximum steering angle, plus the Ackermann inner-wheel angle and the radius of each wheel's path.

Calculate a vehicle's static stability factor SSF = track width ÷ (2 × centre-of-gravity height), its rollover threshold in g and the quasi-static rollover speed on a curve, as used in NHTSA rollover ratings.

Calculate longitudinal weight transfer under braking or acceleration — ΔW = W × a × h ÷ L — and the resulting front and rear axle loads from vehicle weight, CG height, wheelbase and g-force.

Estimate the average g-force and impact force on a person in a car crash from the speed and the stopping distance (crumple zone plus seat belt), with the equivalent fall height and a belted vs unbelted comparison.

Work out motorcycle suspension sag from three measurements — fully extended, bike only and with the rider on — and see rider sag as a share of travel, the target range for street, track or off-road and which way to adjust preload.

Plan how many fuel stops a road trip needs and where to make them, from the distance, tank size, fuel consumption, starting fuel level and the reserve you keep — in km and litres or miles and gallons.

Calculate your average speed between two average-speed (section control) cameras from the distance and the time taken, compare it with the limit and see the minimum time needed to stay legal.

Find how old a tire is from the 4-digit DOT date code on the sidewall (week and year), the approximate manufacture date, and when the 6-year and 10-year replacement guidelines are reached.