Percentage Increase Calculator
Increase a number by a percentage, for price rises, raises, tax and growth.
About the Percentage Increase Calculator
Enter a starting value and the percentage to add. The calculator gives the new value, the amount added, the multiplier, and the percentage decrease that would undo it. Use it for price rises, pay raises, adding tax, or growth targets.
To add a percentage, multiply by 1 plus the percentage as a decimal: a 15% raise on 200 is 200 × 1.15 = 230. Undoing it takes a smaller percentage, because the base is now larger.
The formula
New = Old × (1 + p ÷ 100)
- p
- the percentage
- 1 + p ÷ 100
- the multiplier
Worked example
Increase 200 by 15%
- 15% of 200 = 30
- 200 + 30 = 230, or 200 × 1.15
- To get back to 200: decrease 230 by 13.04%
Questions people ask
Is a 10% then 10% increase the same as 20%?
No: 1.1 × 1.1 = 1.21, a 21% increase.
How do I add VAT to a price?
Increase the price by the VAT rate: £100 + 20% = £120.
How do I find the original price before a rise?
Divide by the multiplier: 230 ÷ 1.15 = 200.