Use this free percent change calculator to compare two numbers. Enter the original and new values to calculate the percentage increase or decrease.
Subtract the original value from the new value, divide by the original value and multiply by 100. The original value is the comparison base.
| Question | Answer |
|---|---|
| 100 → 120 | +20% |
| 200 → 150 | −25% |
| 80 → 80 | 0% |
Try these values in the calculator above.
Percent change measures how far a value has moved relative to its starting amount. When the new value is larger, the result is positive and describes a percentage increase. A smaller new value gives a negative result, or percentage decrease.
Suppose a price rises from 80 to 100. The increase is 20, and the starting price is 80. The relative increase is 20 ÷ 80 × 100 = 25%. If the price moves from 100 down to 80, the decrease is 20%, because the starting value is now 100.
Enter the earlier value first and the later value second. The original, or initial value, is the denominator in the percent change formula. Reversing the inputs answers a different question.
A salary changing from 2,000 to 2,200 rises by 10%. Monthly sales changing from 500 to 425 fall by 15%. The formula works for either example because each compares like-for-like amounts with a positive starting value.
Use the same currency, unit and time period for both inputs. Comparing one month’s revenue with a full year’s revenue will produce a mathematical result, but it will not describe a useful growth rate.
A move from 50 to 100 is 100% growth: the new value is twice the original. A move from 50 to 150 is 200% growth: the new value is three times the original. The percentage change is the increase divided by the original, rather than the new value divided by the original.
Percentage change has a starting point. Percentage difference often compares two values without treating either one as the original; a common convention divides their absolute difference by their average. These calculations can produce different answers, so name the measure you need.
Percentage points describe the gap between two rates. A rate rising from 10% to 12% increases by 2 percentage points. Its relative percentage increase is 20%, since (12 − 10) ÷ 10 × 100 = 20. Read the percentage points explanation for more examples.
If you already know the rate and need a new amount, use the add or subtract a percentage app feature. This free page finds the unknown rate between two known amounts.
Use the free percentage change mode on your phone to compare prices, sales or other amounts with a positive starting value.
Relative change from zero is undefined. For negative numbers, some conventions divide by the absolute value of the initial amount. This calculator requires a positive original value so the direction of an everyday comparison is unambiguous.
Yes. Percentage change is free in the app, with ads. Premium adds the other calculators and removes ads.
Ordinary results use up to eight decimal places. Very small or large results use scientific notation. The ≈ symbol marks display rounding, and the formula preserves the significant digits of your input values.
Subtract the new value from the original, divide by the original and multiply by 100 to express the decrease as a positive magnitude. This calculator uses the signed change formula, so a decrease from 200 to 150 is displayed as −25%.
Yes. An increase from 40 to 100 is 150%. Increases have no upper limit. For a positive original value and a nonnegative new value, a decrease reaches 100% when the new value becomes zero.
After 100 falls by 50%, the amount left is 50. Recovering the lost 50 requires an increase of 50 ÷ 50 × 100 = 100% from that smaller base.
