Percentage Calculator
Calculate percentages, percentage changes, increases and decreases instantly with clear explanations and formulas.
Calculation Type
Enter Your Values
What is X% of a given number?
Result
Enter values to calculate
Choose a calculation type and fill in the fields
4 Calculation Modes
Calculate any type of percentage: find a percentage of a number, determine what percent one number is of another, percentage change, or apply increases and decreases.
Precise Results
Get accurate results with clear explanations and the mathematical formula used, so you can understand and verify the calculation.
Free & Private
100% free, no registration required. All calculations happen in your browser. Your data is never sent to any server.
How to Use the Percentage Calculator
Choose the calculation type: percentage of a number, what percent X is of Y, percentage change, or increase/decrease.
Enter your values in the input fields. The labels adjust based on the calculation type you selected.
Click 'Calculate' or press Enter to get your result instantly.
Read the plain-language explanation and formula to understand how the result was calculated.
Why Use Our Percentage Calculator?
Multiple Calculation Types
Four different percentage calculation modes in one tool. No need to search for separate calculators for different percentage problems.
Clear Explanations
Every result comes with a plain-language explanation and the mathematical formula, helping you understand and learn.
100% Client-Side
All calculations run in your browser. No data is sent to any server, ensuring complete privacy for your numbers.
Mobile Friendly
Works perfectly on phones, tablets, and desktops. Calculate percentages anywhere, anytime.
Frequently Asked Questions
How do I calculate X% of a number?
Select 'X% of Y' mode, enter the percentage in the first field and the number in the second field, then click Calculate. For example, 15% of 200 = 30.
How do I find what percentage one number is of another?
Select 'X is what % of Y' mode, enter the part value and the total value. For example, 30 is 15% of 200.
How is percentage change calculated?
Percentage change is calculated as ((new value - old value) / |old value|) x 100. A positive result means an increase, negative means a decrease.
Can I calculate percentage decreases?
Yes. In 'Increase / Decrease' mode, use a negative percentage to calculate a decrease. For example, -20% of 100 gives 80.
Is my data safe?
Yes. All calculations happen entirely in your browser using JavaScript. No data is transmitted, stored, or logged anywhere.