Formula
% increase = (new − original) ÷ |original| × 100New value = value × (1 + % ÷ 100)
- original — the starting value (must not be zero)
- new — the value after the change
The change is always measured against where you started, which is why a rise from 50 to 75 is 50% but a fall from 75 back to 50 is only 33.3%.
Worked examples
From 50 to 75
- What do you want to do?
- Find the % increase between two values
- Original value
- 50
- New value
- 75
Percentage increase
50%
Absolute change: 25
Increase 200 by 15%
- What do you want to do?
- Increase a number by a percentage
- Number
- 200
- Increase by
- 15 %
New value
230
Amount added: 30
Multiplier: 1.15
How it works
Subtract the original value from the new value, divide by the original and multiply by 100. Going from 50 to 75 is a rise of 25, and 25 ÷ 50 × 100 = 50%.
If the new value is lower than the original the answer comes out negative and a note tells you it is really a decrease — the Percentage Decrease Calculator shows the same change as a positive number. For a single signed figure either way use Percentage Change Calculator.
To increase a number by a percentage, multiply by 1 plus the percentage as a decimal. Increasing 200 by 15% gives 200 × 1.15 = 230. This is how a price with tax or a salary with a raise is worked out.
Assumptions and limits
- An original value of zero is rejected because a percentage increase from zero is undefined.
- With a negative original value the change is measured against the size of the original, so the sign of the result can look unexpected.