Percentage increase calculator
Three ways round: the increase between two numbers, a number plus a percentage, and the number before an increase.
Percent change
How much a value went up or down, as a percentage of where it started. A rise shows as +, a fall as −.
From to
Working: (1,290 − 1,200) ÷ 1,200 × 100 = +7.5%
- Difference
- +90
Increase a number by a percentage
Increase by
Working: 1,200 × (1 + 7.5 ÷ 100) = 1,290
- Amount added
- 90
Original value before a percentage change
For questions like “the price after 20% off is 64, what was it?”. This divides; subtracting or adding the percentage gives the wrong answer.
After a , it's . What was it before?
Working: 96 ÷ (1 + 20 ÷ 100) = 80
- The increase was
- 16
Not 76.8: the 20% was worked out on the original, not on 96.
Percentage increase between two numbers
(new − old) ÷ old × 100. Rent going from 1,200 to 1,290 is (1,290 − 1,200) ÷ 1,200 × 100 = 7.5%.
Adding a percentage
Multiply by 1 plus the percentage over 100. 1,200 plus 7.5% is 1,200 × 1.075 = 1,290.
Undoing an increase
To find the number before an increase, divide instead of subtracting. If a price is 96 after a 20% rise, it was 96 ÷ 1.2 = 80. Taking 20% off 96 gives 76.80, which is wrong: the 20% was 20% of 80, not of 96.
Increases over several years
Rises compound. Three years of 5% is 15.76% in total, not 15%. The compound and CAGR calculators handle that.