How do I compare a buy-one-get-one or second-item deal?

For buy one get one free, choose Buy N get M free with Buy 1 and Free 1, and the free item is added to the quantity you get. For a second item at half price, choose Nth item at X% with item 2 paying 50%, and set Items bought to 2. The unit price is what you pay divided by the total quantity you receive, so you can see whether the deal beats a bigger pack.

How does spend-and-save work?

The threshold is checked against price × items bought for that product. For example, spend 100 save 10 on three items at 39.90 (119.70 total) means you pay 109.70. With “For every X spent” on, the saving repeats each time the threshold is reached. For store-wide deals across several products, split the saving yourself and enter each share as a coupon.

What conversions are used?

1 lb = 453.59237 g and 1 oz = 28.3495 g; the Chinese jin is 500 g and the liang 50 g. Volumes use US measures: 1 fl oz ≈ 29.57 ml, 1 cup ≈ 236.6 ml, 1 pint ≈ 473.2 ml, 1 gallon ≈ 3.785 L. A dozen is 12 items and a pair is 2. Only units of the same kind can be compared; weight and volume mixed together are flagged.

Can I compare toilet paper and tissues?

Yes. For tissues, use sheets: enter sheets per box as the size and boxes per item as packs. Toilet paper can be compared per roll, or better, per meter or per 100 sheets, since roll sizes vary a lot. Set the comparison unit to per 100 sheets, per roll or per meter. Detergent and drinks compare well per liter, and eggs per item.

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🛒Unit Price Calculator - Compare Prices per oz, lb, kg or L

Is the 10 lb bag a better deal than two 2 kg bags on a buy-two-get-one-free offer? For each product, enter the price, the size of one pack (grams, ounces, milliliters, items, sheets, rolls or meters), how many packs come in one item (for example a 6-pack) and how many items you’ll buy. The calculator converts everything to the same unit — per 100 g, per pound, per liter, per item, per 100 sheets — highlights the best value and shows how much more each other option costs as a percentage. Units include mg, g, kg, lb, oz, the Chinese jin and liang, ml, cl, L, US fluid ounces, cups, pints, quarts and gallons, pieces, pairs and dozens, sheets, rolls, and lengths from millimeters to yards; units of the same kind are converted automatically, and mixing kinds (like weight and volume) is flagged. Every product can have a deal: percent off, Chinese-style “X 折” pricing, spend-and-save (optionally repeating), Nth item at a discount (such as second item half price), buy N get M free, or a fixed coupon — prices are based on what you actually pay and what you actually get, and you’re warned when a deal’s condition isn’t met. Sort by unit price; your list autosaves in your browser.

Free · No sign-up · Runs in your browserLast updated: 2026-10-26

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How to use Unit Price Calculator

1Enter each product’s price, pack size and unit, packs per item and items bought
2Add any deal: percent off, spend-and-save, second item discount or buy N get M
3Choose the unit to compare by and see the best value highlighted

FAQ

How do I compare a buy-one-get-one or second-item deal?: For buy one get one free, choose Buy N get M free with Buy 1 and Free 1, and the free item is added to the quantity you get. For a second item at half price, choose Nth item at X% with item 2 paying 50%, and set Items bought to 2. The unit price is what you pay divided by the total quantity you receive, so you can see whether the deal beats a bigger pack.
How does spend-and-save work?: The threshold is checked against price × items bought for that product. For example, spend 100 save 10 on three items at 39.90 (119.70 total) means you pay 109.70. With “For every X spent” on, the saving repeats each time the threshold is reached. For store-wide deals across several products, split the saving yourself and enter each share as a coupon.
What conversions are used?: 1 lb = 453.59237 g and 1 oz = 28.3495 g; the Chinese jin is 500 g and the liang 50 g. Volumes use US measures: 1 fl oz ≈ 29.57 ml, 1 cup ≈ 236.6 ml, 1 pint ≈ 473.2 ml, 1 gallon ≈ 3.785 L. A dozen is 12 items and a pair is 2. Only units of the same kind can be compared; weight and volume mixed together are flagged.
Can I compare toilet paper and tissues?: Yes. For tissues, use sheets: enter sheets per box as the size and boxes per item as packs. Toilet paper can be compared per roll, or better, per meter or per 100 sheets, since roll sizes vary a lot. Set the comparison unit to per 100 sheets, per roll or per meter. Detergent and drinks compare well per liter, and eggs per item.