# Unit Rate Calculator

URL: https://speedycalculator.com/calculators/math/unit-rate/
Last updated: 2026-10-30

> The unit rate calculator divides one quantity by another to give the rate per one unit – price per item, kilometres per litre, words per minute – and the inverse rate.

## Inputs

- Quantity a (e.g. total price)
- Quantity b (e.g. number of grams)
- Express per how many units of b?

## Results

- Unit rate a ÷ b
- Rate per chosen number of units
- Inverse rate b ÷ a

## Formula

```
Unit rate = a ÷ b (per 1 unit of b)
```

## Explanation

Unit rates make comparisons fair: a 750 g box for $4.50 costs $0.006 per gram, a 1 kg box for $5.40 costs $0.0054 per gram, so the bigger box is better value.

### How to use the Unit Rate Calculator

- **Quantity a (e.g. total price)**
- **Quantity b (e.g. number of grams)**
- **Express per how many units of b?**

Results update as you type, and everything is calculated in your browser.

### How it works

Divide the first quantity by the second. The inverse rate b ÷ a answers the reverse question (how many units of b for one unit of a).

### Inputs explained

FieldWhat to enterQuantity a (e.g. total price)A numberQuantity b (e.g. number of grams)A numberExpress per how many units of b?A number

### What each result means

- **Unit rate a ÷ b** = [Quantity a (e.g. total price)]÷[Quantity b (e.g. number of grams)]
- **Rate per chosen number of units** = [Quantity a (e.g. total price)]÷[Quantity b (e.g. number of grams)]×[Express per how many units of b?]
- **Inverse rate b ÷ a** = [Quantity b (e.g. number of grams)]÷[Quantity a (e.g. total price)]

### Example values

How the main result changes when **Quantity a** changes and everything else stays at the example values above:

Quantity a (e.g. total price)Unit rate a ÷ b2.250.0033.380.00454.50.0065.630.00756.750.00990.012

## Worked example

Inputs — Quantity a (e.g. total price): 4.5; Quantity b (e.g. number of grams): 750; Express per how many units of b?: 100.

Results — **Unit rate a ÷ b = 0.006**; Rate per chosen number of units = 0.6; Inverse rate b ÷ a = 166.66666667.

## Key terms

- **Rate**: A ratio comparing quantities with different units.

## FAQ

**What is a unit rate?**
A rate with a denominator of 1, such as $0.006 per gram.

**How do I compare prices?**
Compute the price per unit for each option; the lower one is better value.

**Is speed a unit rate?**
Yes – kilometres per one hour.

**Why show a rate per 100 units?**
Small unit rates are easier to read per 100 g or per 100 km.


## Sources

- [OpenStax – Prealgebra 2e](https://openstax.org/details/books/prealgebra-2e)
- [Wolfram MathWorld – Fraction](https://mathworld.wolfram.com/Fraction.html)