Unit Rate Calculator
Turn any quantity-and-count pair into a unit rate — the amount per one unit — and see the reciprocal rate too.
How it works
unit rate = quantity ÷ number of units · reciprocal rate = number of units ÷ quantity
A unit rate expresses how much of something corresponds to exactly one of another — miles per hour, dollars per item, calories per serving. You get it by dividing the quantity by the number of units so the denominator becomes 1. Unit rates make different-sized deals directly comparable, which is why "price per 100 g" on a shelf label is a unit rate.
Worked example
If a car travels 120 miles on 8 gallons, the unit rate is 120 ÷ 8 = 15 miles per gallon. The reciprocal rate, gallons per mile, is 8 ÷ 120 ≈ 0.0667 — useful when you want fuel used per mile instead.
Sources: Rate (mathematics) — Wikipedia
Frequently asked questions
What is a unit rate?
A unit rate is a ratio with a denominator of 1: it tells you the amount per single unit, such as 15 miles per 1 gallon or $2.50 per 1 kg. You compute it by dividing the total quantity by the number of units.
How do unit rates help me compare prices?
Convert each option to price per common unit (per 100 g, per litre, per item) and the cheapest per-unit figure is the best value regardless of package size. That is exactly what a unit rate does, which is why supermarkets print it on shelf tags.
What if the number of units is zero?
Dividing by zero is undefined, so a unit rate is not defined when there are zero units. The calculator flags this instead of returning an infinite or nonsensical value.
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This calculator is for educational purposes. Double-check important results before acting on them.