Shopping
Percentage saving between two packs
Expresses the gap as a percentage of the higher rate, so a 0.04 difference on 0.6 reads as 6.6666667%.
The Formula
Saving = (dearer unit price - cheaper unit price) / dearer unit price x 100
Expresses the gap as a percentage of the higher rate, so a 0.04 difference on 0.6 reads as 6.6666667%.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| U_dear | Unit price of the dearer pack | currency per goods unit | The larger rate, which forms the denominator of the fraction. |
| U_cheap | Unit price of the cheaper pack | currency per goods unit | The smaller rate, subtracted from the dearer one. |
What Each Symbol Means
U_dearcurrency per goods unit
Unit price of the dearer pack
The larger rate, which forms the denominator of the fraction.
U_cheapcurrency per goods unit
Unit price of the cheaper pack
The smaller rate, subtracted from the dearer one.
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.