Percentage Calculator

Calculation

Percent (%)

Of value

Enter both numbers to see the result.

About this percentage calculator

This free percentage calculator handles the three most common percentage questions in one place. Use it to find a percent of a number (for example 20% of 150), to find what percentage one value is of another (30 is what percent of 150), and to calculate percentage increase or decrease between an old and a new value. The result updates as you type, right in your browser, with no sign-up and no cost.

Percentages come up everywhere: discounts and sales tax, tips, exam scores, interest, and statistics. Doing the math by hand is easy to get wrong, so this tool keeps it quick and accurate.

How to use it

Pick the calculation type from the menu, enter the two numbers, and read the answer. The field labels change to match the calculation you chose so you always know what to type.

How the percentage calculator works

This tool covers the three percentage questions people ask most, each with a simple formula:

Percent of a number:  result = (X ÷ 100) × Y
What percent X is of Y:  result = (X ÷ Y) × 100
Percentage change:  result = ((new − old) ÷ |old|) × 100

Pick the mode that matches your question, enter the two numbers, and the answer updates instantly.

Example calculation

20% of 150 = (20 ÷ 100) × 150 = 30. And going from 100 to 150 is a 50% increase.

Key features

Three modes: percent of, what percent, and change
Handles percentage increase and decrease
Instant, accurate results as you type
Free, private, and no sign-up

When to use it

Working out discounts, tips, and sales tax
Finding a grade or test score percentage
Comparing price or value changes
Everyday math at school, work, or home

Frequently asked questions

What can this percentage calculator do?

It finds a percent of a number, what percent one value is of another, and the percentage increase or decrease between two values.

How do I calculate a percentage increase?

Choose the percentage change mode, enter the old and new values, and it shows the increase or decrease as a percentage.

Is it free?

Yes, completely free with no sign-up, running in your browser.