How to use the percentage calculator
Find a percentage of a number, and what percent one number is of another. Enter percent, number, compare value in the fields above; the percent of number, what percent is y of num, percent change from num to y are computed instantly and plotted on the chart so you can see how the answer changes.
Formula
Variables
- p — Percent (%)
- num — Number
- y — Compare value
Worked example
With percent = 15 %, number = 200, compare value = 50, the calculator gives percent of number ≈ 30; what percent is y of num ≈ 25 %; percent change from num to y ≈ -75 %.
Frequently asked questions
What is the formula for the percentage calculation?
Percent of number = p / 100 × num. What percent is y of num (%) = 100 × y / num. Percent change from num to y (%) = 100 × (y-num) / num. Here p is percent (%), num is number, y is compare value.
What inputs do I need for the percentage calculator?
You need percent in %, number, compare value. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use this calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.