Unit Price Calculator
Find the price per unit and compare two package sizes to see which option is cheaper per ounce, gram, liter, item, or serving.
Single item unit price
Enter the total price, the quantity in the package, and the unit.
Price paid for the whole package.
Amount in the package, in the unit you pick.
Unit price
£0.3119
per oz
£4.99 ÷ 16 ozs = £0.3119 per oz
Price in other weight units
Compare two options
Compare two package sizes to find which is cheaper per unit. Weight and volume units are converted automatically.
Option A
Unit price: £0.01 per g
Option B
Unit price: £0.008 per g
Option B is cheaper per unit
Option B costs about 20% less per g.
Option A
£0.01
per g
Option B
£0.008
per g
Difference
£0.002
per g
Formula
How unit price is calculated
Unit price tells you what you pay for a single unit, so you can compare packages of different sizes on a level footing. The smaller the unit price, the less you pay per unit.
Unit price
Unit price = Total price ÷ Quantity
Divide the total price by the quantity in the package to get the price for one unit.
Convert to a base unit
Base quantity = Quantity × Unit factor
For weight, quantities convert to grams; for volume, to milliliters. This lets different package sizes be compared fairly.
Compare
Cheaper = lowest price per base unit
After converting, the option with the lowest price per base unit is the one that is cheaper per unit.
Examples
Worked unit price examples
Price per ounce
A snack pack costs £4.99 for 16 ounces. The unit price is 4.99 ÷ 16, or about £0.3119 per ounce.
Price per item
A box of 24 items costs £12.00. The unit price is 12 ÷ 24, or £0.50 per item.
Weight comparison
£5.00 for 500 g is £0.01 per gram, while £8.00 for 1 kg is £0.008 per gram, so the 1 kg pack is cheaper per unit.
Basics
How unit price comparison works
Divide to compare
Unit price turns a total price into a per-unit cost, so a small pack and a large pack can be compared.
Compatible units convert
Weight units convert through grams and volume units through milliliters, so ounces, pounds, grams, and kilograms can be compared.
Incompatible units do not
Weight cannot be compared with volume, and count units only compare when they match exactly.
Similar products only
Use unit price for like-for-like products. Quality, concentration, and serving size still matter.
Good to know
Cheaper per unit is not always better
A lower price per unit is a useful signal, but it is only one factor. A larger package is only a saving if you use it before it spoils, and two products at the same unit price can differ in quality, concentration, or serving size. For groceries and household goods, treat the result as "cheaper per unit" rather than "better," and compare products that are genuinely similar before deciding.
FAQ
Unit price calculator questions
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Estimate only. This calculator is for general planning and education, not financial, tax, investment, legal, lender, or professional advice. Actual results can vary based on rates, fees, taxes, market conditions, lender rules, employer rules, contribution limits, and local regulations. Verify important decisions with a qualified professional, lender, official source, or relevant institution.