Unit Price Calculator
Find the price per unit so you can spot the best value.
How to use the Unit Price Calculator
- Enter the total price.
- Enter the quantity (grams, items, ml, etc.).
- See the price per single unit.
Unit price = Total price ÷ Quantity
About the Unit Price Calculator
Divide a total price by a quantity and you get the price of one unit — one gram, one millilitre, one sheet, one tablet. That is all this does, and it is the most effective defence against confusing packaging. It shows the unit price to four decimals, the price per 100 units (the friendlier number to compare), and how many units you get per unit of currency. Shelf labels often show unit pricing, but rounded, inconsistently sized, and sometimes in units that do not match the product beside it.
The assumption this defeats is that the bigger pack is always cheaper per unit. It very often is, which is exactly what makes the exceptions work — "value" and "family" labelling encourages you to stop checking, and the larger size can quietly cost more per gram than the standard one. Sizes that resist comparison, like 375 g against 500 g, do the same job. Checking is worth it precisely because the answer is usually, but not reliably, in the big pack's favour.
Compare like with like: run each product separately using the same unit. Two limitations — a lower unit price is not the better buy if the extra will spoil or sit unused, and this cannot see multibuy promotions, so calculate on what you will actually pay. Pair it with the discount calculator to work out a sale price first, then compare.
Frequently asked questions
How do I compare two products?
Run each one separately and compare the results using the same unit — price per 100 g against price per 100 g, never per 100 g against per item. The lower unit price is the better value on price alone. This calculator handles one product at a time by design.
Is the bigger pack always cheaper per unit?
No, and that assumption is what the trick relies on. It usually is cheaper, which is why people stop checking — and that is precisely when a "value" pack can cost more per gram than the standard size. It takes seconds to verify.
What quantity should I enter?
Whatever is on the label — grams, millilitres, sheets, items, servings — as long as you use the same unit for everything you are comparing. If one pack lists 1.5 kg and another 800 g, convert one of them to the other's unit first.
Should I always buy the lowest unit price?
Only if you will use it. Unit price ignores spoilage, expiry dates, storage space and whether you actually want that much. Cheap per gram is not cheap if a third of it goes in the bin.
Why is the price per unit shown to four decimals?
Because per-unit prices are often tiny — a single gram may cost a fraction of a cent — and rounding to two decimals would show several different products as identical. The per-100-units row is there when you want a readable number.
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