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Normalising to a common unit
Scaling the base rate to a fixed reference is what makes packs of different sizes directly comparable.
The Formula
Unit price per 100 g = (price / quantity) x 100
Scaling the base rate to a fixed reference is what makes packs of different sizes directly comparable.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| 100 | Common reference quantity | goods unit | Use 100 g, 1 kg, 1 litre or 1 item, whichever keeps the numbers readable. |
| U | Base unit price | currency per goods unit | Price divided by quantity, before any scaling to the common reference. |
What Each Symbol Means
100goods unit
Common reference quantity
Use 100 g, 1 kg, 1 litre or 1 item, whichever keeps the numbers readable.
Ucurrency per goods unit
Base unit price
Price divided by quantity, before any scaling to the common reference.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to calculate unit price page applies this equation to a concrete case, shows every intermediate step, and names the mistakes that produce a wrong answer even when the algebra is right.
Where This Formula Appears
This equation is the working core of How To Calculate Unit Price, filed under Everyday Life. Every number the guide produces comes from substituting into this one line.