Percentage Increase Calculator
Enter an old value and a new value to see the percentage increase, or add a percentage to any number. The answer updates as you type.
Percentage increase from to
An increase of 15.
Add % to
The percentage increase formula
Percentage increase = (new value − old value) ÷ old value × 100
The key point is that you divide by the old value. The increase is measured against your starting point, which is why the same gap gives a different percentage depending on which direction you go.
Worked examples
Each row below uses the formula above. The change is new minus old, and the percentage is the change divided by the old value.
| Old | New | Change | Increase |
|---|---|---|---|
| 50 | 65 | 15 | 30% |
| 80 | 100 | 20 | 25% |
| 1,200 | 1,260 | 60 | 5% |
| 32,000 | 34,400 | 2400 | 7.5% |
In the last row, a salary rising from 32,000 to 34,400 is a rise of 2,400. Divide by 32,000 to get 0.075, then multiply by 100 for a 7.5% increase.
Adding a percentage instead
If you already know the percentage and want the new number, multiply the original by 1 plus the rate as a decimal. A 15% rise on 200 is 200 × 1.15 = 230. A 7.5% rise on 32,000 is 32,000 × 1.075 = 34,400, which matches the example above.
Common mistakes
Dividing by the new value instead of the old one is the usual error, and it understates the increase. Another is mixing up percentage change with percentage points: a rate moving from 4% to 6% is a rise of 2 percentage points, but a 50% increase in the rate itself.
FAQ
How do you calculate percentage increase?
Subtract the old value from the new value, divide the result by the old value, then multiply by 100. Going from 50 to 65 is a rise of 15, and 15 ÷ 50 × 100 = 30%, so the increase is 30%.
What is the percentage increase formula?
Percentage increase = (new value − old value) ÷ old value × 100. The old value is always the one you divide by, because the increase is measured against where you started.
How do I add a percentage to a number?
Multiply the number by 1 plus the percentage as a decimal. To add 15% to 200, multiply 200 by 1.15 to get 230. The second calculator above does this for you.
What if the answer is negative?
A negative result means the new value is lower than the old one, so it is a decrease, not an increase. Use the percentage decrease calculator if you mainly want to measure falls.
Can a percentage increase be more than 100%?
Yes. If a value more than doubles the increase is over 100%. Going from 40 to 100 is a rise of 60, and 60 ÷ 40 × 100 = 150%.
Why can I not calculate a percentage increase from zero?
The formula divides by the old value, and dividing by zero is undefined. If you start from zero, any increase is infinite in percentage terms, so the calculator shows a dash instead of a number.
What is a 10% increase on $250?
10% of $250 is $25, so the new value is $275. In the calculator's second box, enter 10 and 250.
How do I find the original number before a percentage increase?
Divide the new number by 1 plus the percentage as a decimal. If a value is 138 after a 15% increase, the original was 138 ÷ 1.15 = 120.
Can a percentage increase be more than 100%?
Yes. If a value more than doubles, the increase is over 100%. Going from 20 to 70 is a 250% increase.
Increases that compound
When an increase is applied repeatedly, each rise is calculated on the new, larger amount, so the overall increase is more than the rates added together. For a salary of $40,000 with a 3% raise every year:
| Year | Salary after a 3% rise each year | Total increase on $40,000 |
|---|---|---|
| 1 | $41,200 | 3.00% |
| 2 | $42,436 | 6.09% |
| 3 | $43,709 | 9.27% |
| 5 | $46,371 | 15.93% |
| 10 | $53,757 | 34.39% |
After 10 years the total increase is 34.39%, not 30%. The same effect applies to prices rising with inflation, rent increases and investment growth.
| Rises applied to $100 | Result | Overall increase |
|---|---|---|
| 10% then 10% | $121.00 | 21% |
| 20% once | $120.00 | 20% |
| 50% then 50% | $225.00 | 125% |
| 100% once | $200.00 | 100% |
Working backwards to the original value
If you know the new value and the percentage that was added, divide by 1 plus the rate as a decimal. You cannot simply subtract the percentage from the new value, because the percentage was calculated on the old value, not the new one.
| New value | Increase applied | Original value |
|---|---|---|
| $120.00 | 20% | $100.00 |
| $1,150.00 | 15% | $1,000.00 |
| $66.00 | 10% | $60.00 |
| $2,750.00 | 25% | $2,200.00 |
For example, a price of $120 after a 20% increase was originally $120 ÷ 1.20 = $100, and not $120 minus 20%, which would be $96.
Everyday uses
- Pay rises. Enter your old and new salary to see the exact percentage and compare it with inflation.
- Prices and rent. Check how much a landlord's or supplier's increase really is.
- Business growth. Compare this month's sales or website visits with last month's.
- Fitness. Track how much a lift, distance or speed has improved.
If the second number is lower than the first, the result is negative, which is a decrease. The percentage decrease calculator handles that case, and the percentage difference calculator compares two numbers without a starting point.