Percentage Calculator

Work out X% of a number, what percent one number is of another, or percentage change.

Loading tool…
  • 🔒 Files never leave your device
  • ⚡ Converted in your browser
  • ✅ No account required

Percentage Calculator: The Complete Guide

Solve any everyday percentage problem. Switch between three modes to find X% of a number, work out what percent one value is of another, or calculate the percentage change between two numbers.

Who the Percentage Calculator is for

Students, shoppers, and professionals doing quick percentage math — discounts, scores, tips, and changes.

How to use the Percentage Calculator

  1. Type your values into the fields above — pick your currency or units where the calculator offers them.
  2. Results update automatically as you type; there's no submit button and nothing is sent to a server.
  3. Adjust any input to compare scenarios, then copy the result with a single click.

How it works

X% of Y = X ÷ 100 × Y. 'X is what % of Y' = X ÷ Y × 100. Percentage change from X to Y = (Y − X) ÷ X × 100.

Features

  • Three percentage modes
  • Increase & decrease
  • Instant result
  • Works with any numbers

Everyday percentage math

Percentages express a part out of one hundred, which makes them ideal for comparing proportions — test scores, discounts, interest, and growth. This calculator covers the three questions people ask most: a percentage of a number, the percentage one number represents of another, and the percentage change between two values.

Frequently Asked Questions

How do I calculate percentage change?

Subtract the old value from the new, divide by the old value, and multiply by 100. A rise gives a positive percentage; a fall gives a negative one.

What's the difference between the modes?

'X% of Y' finds a part of a whole; 'X is what % of Y' finds a proportion; '% change' compares two values over time.

Is this calculator free and private?

Yes. It's completely free with no signup, and every calculation runs locally in your browser, so your numbers never leave your device.

You Might Also Need