Quick example
Compare 12 units for $6 with 20 units for $8.40
Option A costs $0.50 per unit. Option B costs $0.42 per unit, saving $0.08 per unit or 16% compared with the higher unit price.
Compare like with like
The quantity units must match
Count
Compare items, servings, sheets, capsules, or another identical count.
Weight
Use ounces for both or grams for both. Convert first when package labels differ.
Volume
Use the same fluid-volume unit for both products.
Usable amount
Account for waste, concentration, or yield separately when packages are not equivalent.
Value is contextual
The cheapest unit is not always the best purchase
A larger package only saves money if it will be used. Quality, shelf life, storage, coupons, tax, and membership fees can also change the practical value.
Common questions
Unit price FAQ
How do I calculate unit price?
Divide price by the amount in the package.
Can package sizes differ?
Yes. That is the purpose of the comparison, but both quantities must use the same measurement unit.
How are savings calculated?
The difference per unit is divided by the more expensive unit price.