Price Per Unit Calculator
Enter the price and the quantity of each option, using the same unit, to see which one costs less per unit. You can compare two or three products.
How to use this price per unit calculator
- Enter the price you pay for option A and the quantity in the package.
- Enter the price and quantity for option B, using the same unit as option A.
- If you have a third option, enter it in the option C boxes, or leave them blank.
- Press Calculate to see the price per unit for each option.
- Pick the lowest price per unit, then think about storage, expiry and how much you will really use.
How to calculate price per unit
The price per unit is the price divided by the quantity, so you can compare packages of different sizes.
- Price per unit = price / quantity
- Best option = the lowest price per unit
- Saving = (highest unit price – lowest unit price) / highest unit price
Worked example
Option A is a 16 oz package for $4.99, so it costs 4.99 / 16 = $0.3119 per ounce. Option B is a 32 oz package for $8.49, so it costs 8.49 / 32 = $0.2653 per ounce. Option B is cheaper per ounce, and the saving is (0.3119 – 0.2653) / 0.3119 = 14.9% less per unit.
The bigger pack is the better deal only if you will use it all. If half of it spoils, the effective unit price is higher than the one in this table.
Stores often show a unit price on the shelf label, but they do not always use the same unit for different brands. Entering your own quantities in one unit avoids that problem. Also look at how fast you will use the product, since a lower unit price only helps if the extra quantity is used before it expires.
Assumptions & limits
- All options must use the same unit. The calculator does not convert between ounces, pounds, liters and counts.
- It compares price only. Quality, brand, shelf life and storage space are your own call.
- Sales, coupons and loyalty discounts should be applied to the price before you enter it.
- Tax and delivery costs are not included unless you add them to the price.
- Prices are shown to four decimals so that small differences are visible, as stores often do on their unit price labels.
Frequently asked questions
How do I calculate price per unit?
Divide the price by the quantity. A $4.99 package with 16 ounces costs $0.3119 per ounce.
How do I compare different sized packages?
Work out the price per unit for each and compare them. The lower figure is the better price.
Is the bigger package always cheaper?
Not always. Check the price per unit rather than assuming.
What units should I use?
Any unit, as long as it is the same for all options. Convert first if one is in ounces and another in pounds.
Does it include coupons?
Apply the coupon to the price before you enter it.
Can I compare three products?
Yes. Fill in the option C boxes.
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Last updated: November 2026