How do I calculate percent increase?

Use the % Increase/Decrease tab, enter the original and new value, and the tool shows the percent change.

What is a reverse percentage?

It finds the original number when you know a result and what percent that result represents.

Is my data sent anywhere?

No, every calculation happens locally in your browser.

Percentage Calculator

Calculate X% of Y, percent change, and reverse percentages.

Works Offline

Privacy First

No Login

No API

Percentage Calculator

Choose a calculation mode

Percentage (%)

Of value (Y)

20% of 150 is:

Result

Updates live as you type

20% of 150

What percent

25%

Difference

Percent change

+25% (increase)

Original number

250

About the Percentage Calculator

A complete percentage toolkit: find what X% of a number is, work out what percent one number is of another, calculate percent increase or decrease, and reverse-engineer an original value from a percentage result.

Examples

20% of 150

20% of 150

Output

Related tools

Compound Interest Calculator

Math & Numbers

Project investment growth with compounding and recurring contributions.

Fraction Calculator

Math & Numbers

Add, subtract, multiply, divide, and simplify fractions.

GCD & LCM Calculator

Math & Numbers

Find the greatest common divisor and least common multiple of numbers.

Logarithm & Exponent Calculator

Math & Numbers

Compute logarithms of any base and exponentiation results.

Matrix Calculator

Math & Numbers

Add, multiply, transpose, and invert matrices with an editable grid.

Number Sequence Generator

Math & Numbers

Generate arithmetic, geometric, or Fibonacci-like number sequences.

Frequently asked questions

Version 1.0.0 · Updated 2026-08-06 · Runs entirely in your browser