How do I calculate percentage increase?

Subtract the old value from the new value, divide by the old value, and multiply by 100. From 40 to 50 is (50 − 40) ÷ 40 × 100 = 25%.

How do I increase a number by a percentage?

Multiply it by 1 plus the percent as a decimal. 80 increased by 15% is 80 × 1.15 = 92.

Can percentage increase be more than 100%?

Yes. Going from 20 to 50 is a 150% increase. Anything more than doubling is over 100%.

What if the new value is smaller?

The result is negative, which is a percentage decrease. From 50 to 40 is −20%.

Is this the same as the percentage calculator?

No. The percentage calculator finds X% of Y or what percent X is of Y. This page measures change between two values.

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Percentage Increase Calculator

Find the percent increase (or decrease) from an old value to a new one, or raise a number by a set percent.

Percent change from old to new

Old value

New value

Percent change

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Difference

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Increase a number by a percent

Starting number

Increase by (%)

Result

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Amount added

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How to calculate a percentage increase

Percentage increase compares a new value with where it started. The formula is (new − old) ÷ old × 100. If a price goes from $40 to $50, the change is 10, and 10 ÷ 40 × 100 = 25%. The first calculator on this page does exactly that, and it also handles drops: if the new value is lower, the result is negative and labeled as a decrease.

The base is always the old value. That’s why a 25% increase followed by a 25% decrease doesn’t bring you back to where you started: $40 up 25% is $50, but $50 down 25% is $37.50. The second move uses a bigger base.

Increasing a number by a percent

To add a percent to a number, multiply by (1 + percent ÷ 100). An $80 item with a 15% markup is 80 × 1.15 = $92. Use the second calculator for markups, price increases, rent escalations, and raises. If you only need a slice of a number, such as 15% of 80 = 12, the plain percentage calculator is the quicker tool.

Raises, prices and investments

A raise from $50,000 to $54,000 is an 8% increase. To see what that does to each check after tax and FICA, run both salaries through the paycheck calculator. A rent change from $1,500 to $1,620 is also 8%; comparing that against your budget is easier on the affordability calculator.

For a stock or fund, the price change alone isn’t your return. Commissions and fees come off the gain, so use the stock profit calculator for a closed trade, or the ROI calculator when you have a total cost and a total value.

Percent change vs percentage points

If a rate goes from 4% to 5%, it rose by one percentage point, but by 25% in percent-change terms (1 ÷ 4 × 100). Mortgage and savings rates are usually quoted in points. When you compare rates, say which one you mean; when you compare dollar values, percent change is the useful number.

Limits

Percent change is undefined when the old value is zero, because you can’t divide by zero. The calculator tells you instead of printing a misleading number. Results are plain arithmetic, rounded to four decimals for display. They are educational math only, not tax or investment advice.

FAQ

How do I calculate percentage increase?: Subtract the old value from the new value, divide by the old value, and multiply by 100. From 40 to 50 is (50 − 40) ÷ 40 × 100 = 25%.
How do I increase a number by a percentage?: Multiply it by 1 plus the percent as a decimal. 80 increased by 15% is 80 × 1.15 = 92.
Can percentage increase be more than 100%?: Yes. Going from 20 to 50 is a 150% increase. Anything more than doubling is over 100%.
What if the new value is smaller?: The result is negative, which is a percentage decrease. From 50 to 40 is −20%.
Is this the same as the percentage calculator?: No. The percentage calculator finds X% of Y or what percent X is of Y. This page measures change between two values.