Cash Back Calculator
Add up monthly and yearly credit card cash back across five spending categories with their own rates and caps, subtract the annual fee, add a sign-up bonus, compare with a flat-rate card — or check whether a cash-back rebate beats a low-APR loan offer.
How it works
Cash back = Σ (category spend up to the cap × category rate + spend above the cap × base rate) · Monthly = yearly ÷ 12 · Effective rate = cash back ÷ total spend · Net = cash back − annual fee (+ sign-up bonus in year 1) · Rebate vs low APR: compare upfront + all loan payments for (price − down − rebate) at the standard rate with (price − down) at the promotional rate
Cash back is each category’s spending times its reward rate, summed up. Many cards cap the bonus rate — for example 3% or 6% on the first $6,000 of groceries a year, or 5% on $1,500 a quarter in a rotating category — and pay the base rate above it. The effective rate, total cash back divided by total spend, is your real blended reward; it is usually well below the headline rate because most spending falls in the base category. An annual fee comes straight off the reward, and a sign-up bonus counts only if you hit the required spend in time. Comparing with a flat-rate card (often 2% on everything) shows whether the bonus categories are worth it for your spending, and the fee break-even shows how much you must spend for a fee card to win. If you carry a balance, card interest usually outweighs any reward. The second mode answers a different cash-back question: a car dealer offers either a rebate or a low promotional rate. The calculator finances the price minus the rebate at the rate you can get elsewhere, and the full price at the promotional rate, then compares the total of all payments.
Worked example
$600 groceries at 3%, $200 gas at 2% and $800 on everything else at 1% earn $18 + $4 + $8 = $30 a month, or $360 a year — an effective 1.88% on $1,600 of spending. A flat 2% card would pay $384 a year on the same spending, $24 more. For a $35,000 car with $5,000 down, a $2,000 rebate financed at 7% over 60 months costs $554.43 a month ($33,266 in payments), while 1.9% on the full $30,000 costs $524.52 ($31,471), so the low APR saves about $1,795. The rebate would win only if you could borrow below about 4.7%.
Frequently asked questions
Is a high-rate bonus category worth it?
Only if you spend enough there to beat a flat-rate card. Enter your real spending and a flat rate to compare: 5% on $100 a month earns $60 a year, less than 2% on $600 a month ($144).
Does an annual fee change the picture?
Yes. Subtract the fee from your yearly cash back to find the net reward. The calculator also shows how much you must spend each month for the fee card to beat a no-fee flat-rate card.
How do spending caps work?
Many cards pay the bonus rate only up to a limit — say $6,000 a year at a supermarket or $1,500 a quarter in a rotating category — and the base rate above it. Enter the cap under More options and the spending above it earns your “everything else” rate.
Does carrying a balance cancel out rewards?
Almost always. Card interest (often 20%+ APR) dwarfs 1–5% rewards. Turn on “I carry a balance” to see the interest next to your cash back.
Should I take the dealer’s cash back or the low APR?
Compare the total cost. Take the rebate if you pay cash or can borrow elsewhere at a low rate; take the promotional rate if the interest it saves is larger than the rebate. The break-even rate shows where the two are equal.
Related calculators
This is an educational estimate, not financial advice. Confirm figures with your lender, advisor or tax professional.