Percentage Calculator
Four percentage calculators in one place: percent of a value, what percentage one number is of another, and percentage increase or decrease. Each answer shows the formula used.
How to use the percentage calculator
Pick the calculation you need, type your two numbers and press Calculate. The large answer updates instantly and the line underneath shows exactly which formula was applied, so you can copy the working into your own notes.
The formulas
- X% of Y: (X ÷ 100) × Y
- X as a percentage of Y: (X ÷ Y) × 100
- Percentage increase: ((new − old) ÷ old) × 100
- Percentage decrease: ((old − new) ÷ old) × 100
Worked examples
20% of 500 = 100. 100 is 20% of 500. 100 rising to 150 is a 50% increase. 150 falling to 100 is a 33.33% decrease.