Percentage calculator
20 ÷ 80 × 100
Percentage = part ÷ whole × 100
Formula
Part ÷ whole × 100
How the calculation works
Find what percentage a part represents of a whole. Enter each measurement in the unit shown beside the input. The result updates when you change a value; incomplete or unsupported inputs display an explanation.
Worked example
20 out of 80 is 20 ÷ 80 × 100 = 25%.
When to use this calculator
Use this for scores, survey responses, or the share of a total.
Common mistakes and limits
The whole must be greater than zero. Keep part and whole in the same unit.
Check your result
Check that all measurements describe the same object or time period. Repeat the calculation with unrounded values, then round only the final quantity to a precision suitable for the task.
Frequently asked questions
Does this calculator need an account?
No. Calculations run in your browser without an account.
How precise is the displayed result?
The display rounds to six decimal places. Measurement uncertainty can be larger than this rounding.
