Percentage Calculator

Work out percentages fast: X% of a number, what percent one number is of another, and percentage increase or decrease between two values.

Select Calculation Type

What is X% of Y?

Percentage (%)

Of Number

Common Examples:

Calculate 15% tip on $50 bill
Find 20% discount on $100 item
Calculate test score: 45 out of 50
Find percentage increase in salary

About Percentage Calculator

The Percentage Calculator handles the four percentage questions that come up most: what is X% of Y, what is Y increased by X%, what is Y decreased by X%, and what percentage is X of Y. Pick the type of calculation, fill in two numbers, and get the answer immediately.

It is useful for tips, sales, grades, salary changes, tax and interest, anywhere you need a quick percentage without opening a spreadsheet. Calculations run in your browser.

How to use the Percentage Calculator

Choose the calculation type at the top: Basic, Increase, Decrease or Difference.
Basic: enter the percentage and the number to find "X% of Y".
Increase or Decrease: enter a base value and a percentage to get the new value.
Difference: enter a part and a whole to see what percentage the part is of the whole.
Click the calculate button to see the result.

What it can do

Percentage of a number

For example 15% of 50 for a tip.

Increase and decrease

Apply a percentage rise or fall to any base value, such as a 20% raise or 15% price drop.

What percent is X of Y

Turn a score such as 45 out of 50 into 90%.

Built-in examples

Quick examples show common uses like tips, discounts and test scores.

When it is useful

Working out a restaurant tip or sales tax.
Converting an exam score into a percentage grade.
Finding a new salary or price after a percentage change.
Checking how much of a budget has been spent.

Good to know

Percentage increase and decrease are not symmetrical: a 50% increase followed by a 50% decrease does not return you to the starting value.
Results may be rounded for display. Use the exact value if you need more decimals for accounting.

Read the guide: Calculators Guide 2026

Frequently Asked Questions

Q.How do I calculate a percentage of a number?

Multiply the number by the percentage and divide by 100. For example, 25% of 200 is 200 x 25 / 100 = 50.

Q.How do I calculate a percentage increase?

New value = original x (1 + percentage / 100). A 20% increase on 100 gives 120.

Q.How do I find what percentage one number is of another?

Divide the part by the whole and multiply by 100. 45 out of 50 is 45 / 50 x 100 = 90%.

Q.Why is a 50% rise then a 50% fall not back to the start?

The second percentage applies to the larger number. 100 rises to 150, then 50% of 150 is 75 off, leaving 75.

Q.Can I use decimals, like 7.5%?

Yes, enter decimal percentages and values.

Q.Is my input stored?

No, everything is calculated in your browser.