Content reviewed: 24 September 2026
How to calculate a percentage of a value
This calculator answers a common percentage question: what is X% of Y? Enter the percentage in the first field and the value in the second. The result is the proportional part of that value.
Formula
Percentage amount = (percentage ÷ 100) × value
Dividing by 100 converts the percentage into a decimal multiplier. For example, 15% becomes 0.15.
Worked example
To find 15% of 250: 15 ÷ 100 = 0.15, then 0.15 × 250 = 37.5.
When this calculator is useful
- Finding a discount amount before subtracting it from a price.
- Calculating a commission, tip, tax portion or contribution expressed as a percentage.
- Checking a percentage calculation from a spreadsheet, invoice or report.
Percentage of a value vs percentage change
This page calculates a percentage of a value. If you want to measure how much a number increased or decreased relative to an earlier number, use the Percentage Change Calculator.
For a deeper explanation of percentage increase, decrease and reverse calculations, read the Percentages Made Simple guide.