Unit Price Calculator
Find the price per unit to compare products of different sizes.
Is the big pack really cheaper? Enter the total price and the quantity (grams, milliliters, pieces — anything), and this tool gives you the price per single unit. Compare that number between products to spot the best value, no matter the pack size.
Formula / method
Examples
0.009 / g
2.00 each
Finding the price per unit
The unit price is the total price divided by the quantity, giving a cost per litre, per kilogram, per item or per any unit you choose. Comparing unit prices is the reliable way to tell which package is genuinely cheaper when brands sell different sizes.
For example, a 400 g jar at 3.20 costs 0.80 per 100 g, while a 750 g jar at 5.25 costs 0.70 per 100 g, so the larger jar is the better value despite the higher sticker price.
Smarter shopping comparisons
Always compare using the same unit for both products, and use a unit small enough to expose the difference, such as per 100 g rather than per kilogram. Watch for packaging tricks where a 'bonus' size is not actually cheaper per unit.
Bigger is not always better value, since bulk buys can carry a premium or go to waste before use. To turn a price difference into a percentage saving, pair this with the Percentage Calculator.
Where it's used
- Comparing two package sizes of the same product on a grocery shelf, per 100 g or per litre
- Deciding whether a 'family size' or bulk pack is genuinely cheaper per unit
- Comparing a store brand against a name brand sold in different quantities
- Working out cost per sheet, roll or load for paper towels or detergent
- Checking cost per item when products are priced by the pack
Real-world examples
- A 400 g jar of coffee at $3.20 is $0.80 per 100 g, while a 750 g jar at $5.25 is $0.70 per 100 g, so the larger jar is better value despite the higher sticker price
- 12 eggs for $3.60 is $0.30 each; an 18-pack at $4.86 works out to $0.27 each
- A 2 L bottle of soda at $2.40 is $1.20 per litre, versus a 6-pack of 330 ml cans at $3.60 which is about $1.82 per litre
Did you know?
The small per-ounce or per-100 g figure printed on supermarket shelf labels, called unit pricing, spread through US, UK and European stores in the early 1970s as a consumer-protection measure so shoppers could compare value across different pack sizes.
FAQ
How do I compare two products?
Work out the unit price of each (price ÷ quantity) and choose the lower one — it’s the better value even when the pack sizes differ.