Percentage Change Calculator
How much did it go up or down? Get the percentage change, the difference and the working — in four everyday modes.
- Increase / decrease
- With steps
- Live result
- Private
Example: a price goes from 50 to 65 — that is an increase of 30 %.
Example: 200 increased by 15 % is 230; decreased by 15 % it is 170.
Example: 230 is the result of a 15 % increase — the value before was 200. Enter a negative percent for a decrease.
Compares two values when neither is the “old” one. The difference is measured against their average.
Step by step
How to calculate percentage change
Choose the question, enter two numbers.
- 1
Pick a mode
Change from A to B, increase or decrease by a percent, the value before a change, or the difference between two values.
- 2
Enter the values
Type the old and the new value — decimals and negative numbers are fine.
- 3
Read the answer
The result shows the percentage, the absolute difference, the factor and each step of the formula.
Four percentage questions, one tool
The ones that come up with prices, salaries, statistics and grades.
Change from A to B
The classic: old value, new value, percentage increase or decrease.
Apply a percentage
Raise or lower a value by a percent, for example a 4 % pay rise or a 15 % price cut.
Reverse a change
Know the value after a 15 % increase? Get the value it started from.
Percentage difference
Compare two values symmetrically, relative to their average.
Formula and steps
See the calculation written out with your numbers.
Link to your calculation
Copy a link that reopens the calculator with your numbers filled in — handy for sharing or saving a scenario.
Made for phones
Large fields, the right keyboard for numbers and a layout that fits small screens.
Private by design
Everything is calculated in your browser. Your numbers are not sent to a server.
Percentage change, explained
Percentage change compares a new value with an old one: change = (new − old) ÷ |old| × 100. If rent goes from 1,200 to 1,290, the change is 90 ÷ 1,200 × 100 = 7.5 %. A positive result is an increase, a negative one a decrease.
Increases and decreases are not symmetrical. A fall of 50 % needs a rise of 100 % to get back to the start, because the second percentage is measured from a smaller base. For the same reason, +10 % followed by −10 % leaves you 1 % below where you began.
Percentage change has a direction: there is a “before” and an “after”. Percentage difference has none; it compares two values against their average and is used when neither is the reference, for example the prices of two shops. And a change from 4 % to 5 % is one percentage point, but a 25 % increase.
How much rise undoes a fall
| Decrease | Increase needed to recover | Factor |
|---|---|---|
| −10 % | +11.1 % | × 1.111 |
| −20 % | +25 % | × 1.25 |
| −25 % | +33.3 % | × 1.333 |
| −50 % | +100 % | × 2 |
| −75 % | +300 % | × 4 |
Tips
- For “X % of Y” and “X is what percent of Y” use the Percentage Calculator.
- Sale prices and stacked discounts are quicker in the Discount Calculator.
- To see how prices changed over decades, try the Inflation Calculator.
- A change from zero has no percentage: there is nothing to compare with. Report the absolute difference instead.
Frequently asked questions
Can’t find your answer? Contact us — we reply quickly.
What is the formula for percentage change?
Subtract the old value from the new value, divide by the absolute value of the old value and multiply by 100: (new − old) ÷ |old| × 100.
How do I calculate a percentage increase?
Use the same formula. From 50 to 65: (65 − 50) ÷ 50 × 100 = 30 % increase. If the result is negative, it is a decrease.
What is the difference between percentage change and percentage difference?
Percentage change measures the move from an old value to a new one. Percentage difference compares two values without a direction: |a − b| ÷ ((a + b) ÷ 2) × 100.
Why can I not calculate a change from zero?
The formula divides by the old value, and division by zero is undefined. Going from 0 to 5 is an increase of 5, but not of any percentage.
How do I find the original value before a percentage increase?
Divide the new value by (1 + percent ÷ 100). If 230 is the result of a 15 % increase: 230 ÷ 1.15 = 200. Use the “Value before a change” mode.
Are my numbers stored or sent anywhere?
No. The calculation runs in your browser. Your last inputs are remembered on your own device only, so the form is still filled in when you come back; use Reset to clear them.
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