Percent Change Calculator 2026 — Increase & Decrease
Find the exact percentage increase or decrease between two values, or apply a percentage change to any starting number — instantly, with a full breakdown of the math.
Percent Change or Apply a Percentage?
Use “Percent Change” when you have two values and want to know the percentage difference between them. Use “Apply % Increase/Decrease” when you have a starting number and want to know the result after adding or removing a percentage.
Percent Change Calculator
Enter your old and new value to find the percentage difference
Percentage change is always measured relative to the old value.
Percent Change Result
Percentage increase or decrease, and the raw difference
Enter an old and new value, then click Calculate Percent Change to see the result.
Apply a Percentage Calculator
Enter a starting number and a percentage to increase or decrease it by
Apply Percentage Result
Resulting value after the percentage change
Enter a starting number and a percentage, then click Calculate New Value.
Percent Change Quick Examples
Common percentage change scenarios, worked out using the standard formula: (New − Old) ÷ Old × 100.
| Old Value | New Value | Change | Result |
|---|---|---|---|
| 50 | 75 | +25 | +50% |
| 80 | 60 | −20 | −25% |
| 10 | 25 | +15 | +150% |
| 200 | 150 | −50 | −25% |
| 1,000 | 1,200 | +200 | +20% |
| 500 | 500 | 0 | 0% (no change) |
Percent Change Calculator FAQ
Everything you need to know before comparing values as a percentage in 2026.
Percentage change is calculated as (New Value − Old Value) divided by the absolute value of the Old Value, multiplied by 100. A positive result means an increase and a negative result means a decrease. For example, going from 50 to 65 is a change of (65-50)/50 × 100 = 30% increase.
Percentage change measures the relative change between two values as a ratio, while a percentage point change is simply the arithmetic difference between two percentages. Going from 20% to 25% is a 5 percentage point increase, but a 25% relative percentage increase, since 5 is 25% of 20.
To increase a number by a percentage, multiply it by (1 + percentage/100). To decrease it, multiply by (1 – percentage/100). For example, increasing 200 by 15% gives 200 × 1.15 = 230, while decreasing 200 by 15% gives 200 × 0.85 = 170.
Percentage change can exceed 100% whenever a value more than doubles. For example, going from 10 to 25 is a 150% increase, because the value grew by one and a half times its original size, not just by a fraction of it.
Yes. Percentage change is always measured relative to the original (old) value, so swapping which number is the start and which is the end changes the result. Going from 100 to 150 is a 50% increase, but going from 150 back to 100 is only a 33.3% decrease, not 50%.
Percentage change is undefined when the old value is zero, since you cannot divide by zero — any change from zero is usually described in absolute terms instead. With negative starting values, the standard formula still works mathematically, but the result can be misleading, so it is often clearer to compare the absolute difference directly.