Find the percentage increase or decrease between two numbers. This free percentage change calculator shows the percent change, direction, absolute change and percentage difference.
Enter the original and new values to find the percentage change between them. A rise gives a positive percentage (increase); a fall gives a negative one (decrease).
Percentage change measures how much a value rose or fell relative to its starting point. Percentage difference compares two values relative to their average (order doesn’t matter).
How the Percentage Change Calculator Works
Percentage change tells you how much a value rose or fell compared to where it started. This calculator takes an original and a new value and returns the percent change, the direction of the move, the absolute change, and a separate percentage difference measure that treats both values equally.
Formula: Percentage change = (new value − original value) ÷ |original value| × 100. A positive result is an increase; a negative result is a decrease. The calculator also shows the absolute change (new − original), the ratio (new ÷ original), and the percentage difference = |new − original| ÷ ((|original| + |new|) ÷ 2) × 100, which compares the two values relative to their average instead of the starting point.
- Original value — the starting number you’re measuring change from
- New value — the number you’re comparing against the original
Example Scenarios
| Original value | New value | Percentage change |
|---|---|---|
| 80 | 100 | +25% |
| 50 | 40 | -20% |
| 200 | 150 | -25% |
| 10 | 15 | +50% |
| 120 | 90 | -25% |
| 75 | 100 | +33.33% |
Percentage Change Calculator FAQ
Why is percentage change different from percentage difference?
Percentage change measures movement relative to the original (starting) value, so order matters — going from 80 to 100 is different from going from 100 to 80. Percentage difference instead compares two values relative to their average, so the order you enter them in doesn’t change the result.How do I calculate a percentage decrease?
Enter the higher (starting) number as the original value and the lower number as the new value. The calculator subtracts original from new, divides by the original, and multiplies by 100 — since new is smaller, the result comes out negative, indicating a decrease.What does a negative percentage change mean?
A negative result means the new value is lower than the original — a decrease. The “Direction” field spells this out as “Decrease” whenever new minus old comes out negative, and “Increase” whenever it’s positive.Why can’t the original value be zero?
Percentage change divides by the original value, and dividing by zero is undefined in mathematics. If the original value is 0, there’s no meaningful percentage to calculate no matter what the new value is, so the calculator won’t return a result.What’s the difference between percentage change and the new÷old ratio?
The ratio (new ÷ old) shows the new value as a multiple of the original, like “1.25x” for a 25% increase. Percentage change expresses that same relationship as a percentage relative to the original, subtracting 1 (or 100%) first so it reads as a rise or fall rather than a multiple.How do I calculate percentage change for a decrease in price?
Enter the original (pre-discount) price as the original value and the sale price as the new value. The result will be negative, and the “Absolute change” field shows the exact amount saved in currency units rather than percentage.Related Calculators
Once you have your percentage change, the percentage calculator can help with related percentage-of and percentage-of-total questions, and the ratio calculator is useful if you’d rather express the relationship between two values as a ratio instead. For tracking changes across a grading period, the aggregate percentage calculator combines multiple scores into one overall figure.