Percentage increase calculator
Add a percentage to a value or measure an increase from two values. See the final value and worked calculation.
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Result
Increasing 200 by 15 % gives 230.
Show calculation steps
Multiply the starting number by one plus the percentage divided by 100.
Formula
Calculation steps
- 1 + 15 ÷ 100 = 1.15
- 200 × 1.15 = 230
Numbers are displayed to at most 6 decimal places.
More options
Select the jurisdiction independently of your language. Portugal’s islands and Spain’s other tax territories need separate treatment.
Tax
No verified preset is available. Enter the applicable rate yourself.
Select the jurisdiction independently of your language. Portugal’s islands and Spain’s other tax territories need separate treatment.
This tool performs arithmetic, not legal tax determination. The applicable rate and obligations depend on the transaction, place and date. Confirm them with the official authority.
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How we calculateTry an example
Understand the calculation
How percentage increase works
Subtract the starting value from the new value, divide by the starting value, and multiply by 100. From 120 to 150 the change is 30, and 30 ÷ 120 = 0.25, so the increase is 25%.
Always divide by the starting value. Dividing by the new value (30 ÷ 150 = 20%) answers a different question: how much smaller the old value was than the new one.
Check your answer by going forward
Multiply the starting value by 1 plus the percentage as a decimal. 120 × 1.25 = 150, so 25% is right. The same multiplier adds a percentage to a number in one step: 52,000 × 1.04 = 54,080.
Undoing an increase
If a price is $138 after a 15% rise, the old price was 138 ÷ 1.15 = $120. Taking 15% off $138 gives $117.30, because 15% of the new price is a bigger amount than 15% of the old one. The “Reverse %” tab does this division for you.
Several increases in a row
Two 10% increases add up to 21%, not 20%, because the second 10% applies to the already-increased value. The “Successive %” tab multiplies the changes together and shows the real total, which matters for rent increases over several years, compounding prices and sales growth.
Starting from zero or a negative number
A percentage increase from 0 isn’t defined, since any amount is infinitely larger than nothing. Report the change in units instead. When the starting value is negative, PercentSwift divides by its absolute value so that a move toward zero counts as an increase, and it says so in the result.
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Understand the calculation