Calculator Tools
Free Online Percentage Calculator
Choose a calculation mode below to find a percentage of a number, express one number as a percentage of another, or calculate percentage change.
How to use the percentage Calculator
- Choose the type of percentage calculation you need.
- Enter the two numbers required for that calculation.
- Click 'Calculate' to see the instant result.
- Switch calculation modes any time without losing your entered numbers.
Example
Selecting "What is X% of Y?" with X = 20 and Y = 150 returns 30, since 20% of 150 is 30.
Why use a percentage calculator?
Percentages show up everywhere — discounts, tax, grades, tips, and statistics — but the math shifts depending on what you're solving for. This tool covers the three most common percentage questions in one place, so you don't have to remember the formulas.
Three calculations, one tool
Switch between finding a percentage of a number, expressing one number as a percentage of another, or measuring percentage increase or decrease — all without leaving the page.
Frequently asked questions
Use 'What is X% of Y?' with X as the discount percentage and Y as the original price to find the amount saved.
It's calculated as ((new value − old value) / old value) × 100, shown as a positive number for an increase or negative for a decrease.
Yes, both fields accept decimal numbers for precise calculations.
Yes, completely free with no limits on how many times you can use it.