📊 Percentage Calculator
Three common percentage questions, one tool: find X% of a number, work out what percent one number is of another, or calculate the percentage change (increase or decrease) between two numbers.
How the Percentage Calculator works
Each mode uses the standard percentage formula for that question — multiplication for "X% of Y," division for "what percent is X of Y," and a change-over-original calculation for percentage increase or decrease.
Step-by-step calculation
- 1Choose the question type.
- 2Enter the numbers.
- 3Apply the matching percentage formula.
Worked example
15% of 80 = 12. 12 is 15% of 80. Going from 50 to 65 is a 30% increase.
Percentage Calculator examples
| Percent | Result |
|---|---|
| 5 | 7.5 |
| 10 | 15 |
| 15 | 22.5 |
| 20 | 30 |
| 25 | 37.5 |
| 50 | 75 |
Percent of 150. Other inputs kept at the calculator's default values. Results calculated by this calculator.
Why use a Percentage Calculator?
Solve discounts, tips, grades and changes quickly.
Important factors that can affect your results
- Percent of vs percent change.
- Which number is the original.
- Rounding.
Frequently asked questions
How is percentage change calculated?
(New value − Original value) ÷ Original value × 100 — a positive result is an increase, negative is a decrease.
Can percentages be over 100%?
Yes — for example, going from 10 to 25 is a 150% increase.
Related calculators
Last reviewed November 2026 · How we build and check our tools · Report a problem