Unit Price Calculator

Enter a price and a size for each product to find the price per ounce, per 100 g, per fluid ounce and so on, and see which one is the best value. Units of the same kind are converted for you.

Products (2 to 10 rows; the name is optional; only rows with a price and a size are compared)

Quantity is how many of the same item come in the pack (6 for a 6-pack). Leave it empty for 1. Enter every price either with tax or without tax, not a mix of the two.

Compare the price per

The choice that applies depends on the kind of unit you entered: weight uses the first amount, volume the second, length the third, and counts the last.

Lowest unit price —

The number copied is the lowest unit price (without commas). Unit prices are rounded to 3 decimal places for display (more digits are shown for very small values). The ranking uses the exact values, not the rounded ones.

How the unit price is calculated

Unit price = price ÷ (size × quantity) × the amount you compare by

For example, a 16 oz pack for 3.99 costs 3.99 ÷ 16 = 0.249375 per ounce, which shows as 0.249. A 24 oz pack for 5.49 costs 5.49 ÷ 24 = 0.22875 per ounce, which shows as 0.229, so the larger pack is the better value.

Once every product is expressed per the same amount, sizes no longer matter and the products can be compared directly. "Compared with the lowest" tells you how much more each product costs than the cheapest one, in percent.

Which units can be compared

Units of the same kind are converted automatically.

Weight: g, kg, oz, lb (1 lb = 16 oz = 453.59237 g)
Volume: mL, L, US fl oz, US qt, US gal (1 US gal = 128 US fl oz = 3.785411784 L)
Length: cm, m, in, ft, yd (1 yd = 3 ft = 36 in = 0.9144 m)
Count: each, sheets, rolls and so on

Units of different kinds cannot be compared, so the tool shows an error. Weight and volume are different quantities: 1 fl oz of a liquid does not weigh 1 oz, because the weight depends on what the liquid is. Use one kind for all rows. Fluid ounces here are US fluid ounces; the imperial fluid ounce is a slightly different size and is not included.

The calculation uses exact fractions, so there is no floating-point error, and rounding happens only when the result is shown. Products with exactly the same unit price are all treated as the lowest.

Examples

16 oz for 3.99 and 24 oz for 5.49: per ounce 0.249 and 0.229. The 24 oz pack is the lowest; the 16 oz pack costs 9.02% more.
1 lb for 4.50 and 20 oz for 5.40: per ounce 0.281 and 0.27. The 20 oz pack is the lowest; the 1 lb pack costs 4.17% more.
A 6-pack for 6.00 and a 12-pack for 10.00: per item 1 and 0.833. The 12-pack is the lowest.

Notes

The unit price only compares price against size. It does not consider quality, brand, shelf life, whether you can use it all, or storage space.
Enter every price either with tax or without tax. Shelf labels do not always follow the same rule.
The currency does not matter: the price is just a number. Prices and sizes must be greater than 0, with up to 9 digits before the decimal point and 6 decimal places. Quantity is a whole number from 1 to 9,999. Use a period as the decimal separator; commas are accepted only as thousands separators.
If a label shows a total weight such as "12 × 1.5 oz", enter the total in Size, or enter 1.5 oz as Size and 12 as Quantity.
For other conversions see the Weight Converter and the Volume Converter. For a price after a discount, see the Discount Calculator.

Frequently asked questions

Is a bigger pack always cheaper per ounce?

No. Larger packs are often cheaper per unit, but not always. Compare the unit price, not the pack size.

Can I compare ounces and fluid ounces?

No. Ounces measure weight and fluid ounces measure volume. Use the same kind of unit for every product. If you know the density of the product, convert it yourself first.

How do I compare a pack of 12 with a pack of 18?

Choose "each" as the unit, enter 1 as the size and the number of items as the quantity (or enter the number of items as the size), then compare per 1 each.