How to use it
- Type the price of each product, after any coupon you plan to use.
- Type the size shown on the package and choose its unit. Sizes can be decimals, like 12.5.
- Use “Add item” for up to four products. Each needs a price and a size.
- Read the price per unit. The cheapest option is marked “Best value”. Change “Compare per” to see the same results per ounce, pound, gram or kilogram, or per fluid ounce, milliliter or liter.
Why unit price beats sticker price
The sticker price tells you what leaves your wallet today, but not how much you get for it. Unit price puts packages of different sizes on one scale. Take a $4.00 pack of 16 oz and a $7.00 pack of 2 lb. At first glance the $4.00 pack looks cheaper. Two pounds is 32 oz, so the larger pack works out to about $0.219 per ounce against $0.25 for the smaller one: about 12.5% less per ounce.
The figures here are made-up round numbers for illustration, not real product prices.
Units the calculator can compare
- Weight: ounces (oz), pounds (lb), grams (g) and kilograms (kg).
- Volume: fluid ounces (fl oz), milliliters (ml) and liters (L).
- Count: single items, such as sheets, pods or bags.
Units convert within a group only. Weight, volume and count cannot be turned into one another, because that depends on what the product is. If your items mix groups, the calculator says so instead of guessing.
Things unit price does not tell you
- Whether you will use it all. A cheaper bulk pack is no saving if half of it goes bad.
- Quality and ingredients. Two products with the same unit price can still differ a lot.
- Package contents. Check whether the size on the label is the net amount, and whether a multi-pack size is per item or for the whole pack.
Want to turn a percent off into a final price? Use the discount calculator, or browse the best Amazon deals right now.
Frequently asked questions
- How do I compare unit prices?
- Divide each price by its size, using the same unit for every product. A $4.00 pack of 16 oz costs $0.25 per ounce, and a $7.00 pack of 2 lb (32 oz) costs about $0.219 per ounce, so the larger pack is about 12.5% cheaper per ounce.
- Is the bigger package always the better deal?
- No. Larger sizes are often cheaper per unit, but not always. Sales, coupons and odd pack sizes can flip the result, which is why it pays to compare per-unit prices instead of going by size.
- Can I compare ounces with fluid ounces?
- No. An ounce measures weight and a fluid ounce measures volume, so they are different kinds of unit. The calculator shows a message instead of a misleading answer when the units do not match.
- Does the calculator include tax, shipping or coupons?
- No. It works on the price you type in. To include a coupon, enter the price after the coupon. Add any shipping to the price if you want to compare what each option really costs you.
- Does the calculator store what I type?
- No. The arithmetic runs in your browser and nothing you enter is sent to our servers.