Percentage Increase Calculator
Type the old and new values to get the percentage increase, or switch to adding a percentage to a number, such as a 4% pay rise.
From to , what’s the increase?
Percentage increase
15%
From 1,800 to 2,070 is an increase of 15%.
How this works: Method, 1 source, Checked against 2 worked examples,
How this works
Method
Subtract the old value from the new one to get the increase, divide it by the old value, and multiply by 100. Rent going from $1,800 to $2,070 is an increase of $270, and 270 ÷ 1,800 = 0.15, so the rent went up 15%. Full method
Sources
How it’s tested
2 worked examples for this page are checked by automated tests before every release: given the inputs, the tool must show the expected answer.
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Changes
- Added eight pages for common questions, from percent of a number to percent error and reverse percentages, each with its own method, examples and table.
- Added key facts with a worked example of each formula.
- Redesigned: type the numbers straight into a sentence, with bars on one scale that picture the answer.
- Results now update as you type, with no Calculate button.
- First published.
How to calculate a percentage increase
Subtract the old value from the new one to get the increase, divide it by the old value, and multiply by 100. Rent going from $1,800 to $2,070 is an increase of $270, and 270 ÷ 1,800 = 0.15, so the rent went up 15%.
To go the other way and add a percentage, multiply by 1 plus the percentage as a decimal. A 4% pay rise on 2,400 is 2,400 × 1.04 = 2,496. The multiplier is quicker than working out 4% and adding it, and it chains: two 4% rises are × 1.04 × 1.04 = × 1.0816, an 8.16% rise in total, not 8%.
A percentage increase is always measured from the starting value. That is why going up 25% and then down 25% does not bring you back: the fall is 25% of a bigger number. The table below lists the decrease that exactly undoes each increase.
% increase = (new − old) ÷ old × 100 · new = old × (1 + p ÷ 100)
- Relative change compares a change with the reference (starting) value; expressed in percent it is the percentage change, and its sign shows whether the value rose or fell. Source: Wikipedia, Relative change.
Percentage increases as multipliers, and the decrease that undoes each
Multiply by the factor to apply the increase; the last column is the percentage fall that brings the new value back to the start.
| Increase | Multiply by | On 250 | Decrease to undo it |
|---|---|---|---|
| +1% | 1.01 | 252.5 | 0.99% |
| +2% | 1.02 | 255 | 1.96% |
| +3% | 1.03 | 257.5 | 2.91% |
| +4% | 1.04 | 260 | 3.85% |
| +5% | 1.05 | 262.5 | 4.76% |
| +7.5% | 1.075 | 268.75 | 6.98% |
| +10% | 1.1 | 275 | 9.09% |
| +12.5% | 1.125 | 281.25 | 11.11% |
| +15% | 1.15 | 287.5 | 13.04% |
| +20% | 1.2 | 300 | 16.67% |
Show all 19 rowsShow fewer
| +25% | 1.25 | 312.5 | 20% |
| +30% | 1.3 | 325 | 23.08% |
| +33⅓% | 1.3333 | 333.33 | 25% |
| +40% | 1.4 | 350 | 28.57% |
| +50% | 1.5 | 375 | 33.33% |
| +75% | 1.75 | 437.5 | 42.86% |
| +100% | 2 | 500 | 50% |
| +150% | 2.5 | 625 | 60% |
| +200% | 3 | 750 | 66.67% |
Frequently Asked Questions
What is the percentage increase from 40 to 50?
The increase is 10, and 10 ÷ 40 = 0.25, so it is a 25% increase. Going back from 50 to 40 is a 20% decrease, because the 10 is now divided by 50.
How do I add 20% to a price?
Multiply by 1.2. A $35 item plus 20% is 35 × 1.2 = $42. Adding 20% of $35 ($7) to $35 gives the same answer in two steps.
What does a 100% increase mean?
The value has doubled: the increase is as large as the starting value. A 200% increase means it has tripled.
What if the new value is smaller?
Then it is a decrease, and the formula gives a negative percentage. The calculator says so and shows the size of the fall; the percentage decrease page works it out from the other side.