Unit price calculator
Compare up to four options and see which costs least per unit.
About this tool
Quick answer: Unit price is the cost of one standard unit, such as one item, one ounce or one litre. Divide the price by the quantity. This calculator does it for up to four options, converts units for you and highlights the best value.
How to use it
- Choose the unit to compare by, for example 1 item or 100 grams.
- For each option, enter the price, the quantity and its unit.
- The best value is highlighted, and the others show how much more they cost.
Example: two packs of batteries
| Option A | $12 for 6 batteries = $2.00 each |
|---|---|
| Option B | $20 for 12 batteries = $1.67 each |
| Best value | Option B, 17% cheaper per battery |
The bigger pack costs more in total but less per battery.
Good to know
Comparing different units
You can mix units of the same kind, such as grams and ounces or litres and fluid ounces. The calculator converts them first. You cannot compare weight with volume.
Useful for gadgets
Compare a multi-pack of cables by price per cable, batteries by price per battery, or cable length by price per metre.
Cheapest per unit isn't always best
A bulk pack only saves money if you will use all of it. Check quality, warranty and the return policy as well.
Frequently asked questions
How do I calculate unit price?
Divide the total price by the quantity. A $12 pack of 6 costs $2 per item. For weight or volume, divide the price by the amount in the unit you want to compare, such as per ounce or per 100 grams.
Can I compare different units?
Yes, as long as they measure the same kind of thing: weight with weight, volume with volume, length with length, or items with items. You cannot compare grams with litres.
Is the biggest pack always cheapest per unit?
Often, but not always. Larger packs are sometimes priced higher per unit, so always check the number.
Does this calculator store what I type?
No. The maths runs in your browser and nothing is sent or saved.
Related reading
More tools
This tool uses only the numbers you type. It does not use or show Amazon product data, and nothing you enter is stored or sent.