Percentage of a number
Everyday
How to calculate decrease by percentage
This tool calculates decrease by percentage from Original, Decrease (%). Enter each quantity in its labelled field, then use the formula below to check the calculation.
Formula
original × (1 − percentage ÷ 100)
Worked example
- Original
- 80
- Decrease (%)
- 20
Applying the formula to these values gives 64 .
What should I check?
Work out percentages, discounts, bill splits, recipe amounts and other everyday numbers. Each tool shows its formula and a worked example.
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