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The bigger pack is not always cheaper. Enter the price and size of two options to see the cost per unit and which one actually wins.

A vs BPer unitNo sign-up
Cost per unitbetter deal
A per unit
B per unit

How to compare fairly

Unit price is simply price divided by size, whether that size is grams, millilitres, sheets or count. Put both options in the same unit and the lower price per unit is the better value, regardless of pack size or a tempting bigger number.

500 g at 3.50 vs 750 g at 5.20
0.0070 vs 0.00693 per g, so B wins

When cheaper per unit is not the answer

Per-unit price finds the mathematical best value, but buy what you will actually use: a cheaper large pack is false economy if half of it spoils. Keep the sizes in matching units, grams with grams, and the comparison holds.

Common questions

Unit price FAQ

Any, as long as both products use the same one: grams with grams, millilitres with millilitres, or count with count.

No. As long as both prices are in the same currency, the lower price per unit is the better deal.

Compare in pairs: check A against B, then the winner against C, and so on.

Multi-buys and large packs are not always discounted; sometimes the small size is on offer, which is exactly what unit pricing reveals.