How do I calculate percentage increase?

Subtract the old value from the new one, divide by the old value and multiply by 100. From 50 to 65: (65 − 50) ÷ 50 × 100 = 30%.

How do I increase a number by a percentage?

Multiply it by 1 plus the percentage as a decimal. To add 20% to 80, calculate 80 × 1.20 = 96.

What if the old value is zero?

The percentage increase is undefined, because you cannot divide by zero. Report the absolute change instead.

Is percentage increase the same as percentage change?

Percentage change is the general term. It is called an increase when the result is positive and a decrease when it is negative.

Percentage Increase Calculator

Find the percentage increase between two numbers, or raise a number by a percentage.

Updated September 19, 2026Checked by the editorial team

Original value

New value

Percentage increase

25%

(100 − 80) ÷ 80 × 100 = 20 ÷ 80 × 100

A percentage increase tells you how much bigger a new number is compared with where it started. It is the figure behind price rises, pay raises, traffic growth and rent letters.

This calculator works in both directions: give it an old and a new value to get the increase, or give it a starting number and a percentage to see the result.

How percentage increase calculator works

In the first mode, enter the original value and the new value. The tool subtracts, divides by the original and shows the change as a percentage. If the new number is lower it tells you it is a decrease instead of returning a confusing negative.

In the second mode, enter a number and the percentage to add. The result is the new total and the amount added.

The formula

% increase  =  (New − Old) ÷ Old × 100
New value  =  Old × (1 + Percentage ÷ 100)

The base is always the old value. The old value must not be zero.

Worked example: a price that goes from 50 to 65

Change: 65 − 50 = 15.

Divide by the original: 15 ÷ 50 = 0.30.

Multiply by 100: the increase is 30%.

To go forward instead, 50 × 1.30 = 65.

When to use this tool

Working out how much a rent, subscription or utility price has actually gone up.
Checking a pay raise: 52,000 to 56,160 is an 8% increase.
Reporting growth in visitors, revenue or followers between two periods.
Adding a markup or tax rate to a base price.

Common mistakes to avoid

Dividing by the new number instead of the old one. That answers a different question and gives a smaller figure.
Comparing a percentage increase with a change in percentage points. Going from 10% to 12% is a 2-point change and a 20% increase.
Assuming a 50% increase can be undone by a 50% decrease. It cannot, because the second percentage applies to a larger base.

Frequently asked questions

How do I calculate percentage increase?: Subtract the old value from the new one, divide by the old value and multiply by 100. From 50 to 65: (65 − 50) ÷ 50 × 100 = 30%.
How do I increase a number by a percentage?: Multiply it by 1 plus the percentage as a decimal. To add 20% to 80, calculate 80 × 1.20 = 96.
What if the old value is zero?: The percentage increase is undefined, because you cannot divide by zero. Report the absolute change instead.
Is percentage increase the same as percentage change?: Percentage change is the general term. It is called an increase when the result is positive and a decrease when it is negative.

Learn more

Results are for information only and are not financial, legal or medical advice. The calculation logic is covered by automated tests, and examples on this page are worked out and re-checked before publishing. Spotted a mistake? Tell us.