Unit Pricing Explained
How it works4 min readUpdated May 14, 2026
What unit pricing is
Alongside the headline price, most shelf labels show a smaller figure: the price per standard unit — per 100g, per kilogram, per litre, or per item. That number is the great equaliser. Two products in different-sized packs can’t be compared on total price alone, but their unit prices sit on the same scale, so the cheaper one is obvious at a glance.
Why pack size is a trap
Shoppers assume bigger packs are always better value, and retailers know it. Often the large pack is cheaper per unit — but not always, and the exceptions are where money quietly leaks. A “family size” box can carry a higher per-100g price than the standard box beside it. Promotional pricing plays the same game: a multi-buy can look generous while the per-unit cost is unchanged or worse. Reading the unit price strips the marketing away.
How to use it in practice
Compare like with like: per-100g against per-100g, per-litre against per-litre. When packaging units differ (per item vs per 100g), use whichever measure matches how you actually consume the product. And remember unit pricing only compares value, not whether you need the quantity — a lower unit price on a huge pack is no saving if half of it spoils.
| Pack | Shelf price | Unit price | Better value? |
|---|---|---|---|
| Standard 500g | $3.00 | $0.60 / 100g | Yes |
| Family 1kg | $6.50 | $0.65 / 100g | No — dearer per 100g |
Same product, two packs
Frequently asked questions
- What is a unit price?
- The cost per standard measure — per 100g, per litre or per item — shown on the shelf label so different pack sizes can be compared fairly.
- Is the biggest pack always cheapest per unit?
- No. Usually but not always; some large or “family” packs cost more per unit than the standard size, so always check.
- Does a special always mean a lower unit price?
- No. Some promotions leave the per-unit cost unchanged. The unit price tells you whether a special is genuinely cheaper.