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 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.