Calculators & everyday math
How to Calculate Percentage Change
Percentage change tells you how much a value moved relative to where it started — sales up 12%, a bill down 8%, a score up 40%. This guide walks through the formula, how to read the sign, a spreadsheet version, and the checks that catch the usual errors.
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The formula
percentage change = (new value − original value) ÷ original value × 100
Subtract the original value from the new one to get the change, divide by the original value, and multiply by 100.
Worked examples
| From | To | Change | Percentage change |
|---|---|---|---|
| 100 | 125 | +25 | +25% |
| 100 | 75 | −25 | −25% |
| 250 | 280 | +30 | +12% |
| 80 | 60 | −20 | −25% |
| 40 | 100 | +60 | +150% |
| 64 | 64 | 0 | 0% |
Reading the result
- Positive means the value went up, negative means it went down, and 0% means no change.
- A fall from a positive value to zero is −100%; it only goes beyond −100% if the new value is below zero.
- Increases have no upper limit: doubling is +100% and tripling is +200%.
Checks that catch mistakes
- Divide by the original value, never the new one. From 80 to 60 is −25% (20 ÷ 80), not −33.33% (20 ÷ 60).
- Keep the order: 100 → 125 is +25%, but 125 → 100 is −20%.
- If the original value is 0, stop — percentage change from zero is undefined.
- If the original value is negative, the sign of the result can point the wrong way. The guide on percentage change from zero or a negative number explains why.
In a spreadsheet
With the original value in A2 and the new value in B2, use =(B2-A2)/A2 and format the cell as a percentage. =IF(A2=0,"n/a",(B2-A2)/A2) avoids a divide-by-zero error when the original is 0.
Calculate Percentage Change FAQ
- What is the percentage change formula?
- (new value − original value) ÷ original value × 100.
- How do I calculate a percentage decrease between two numbers?
- Use the same formula; the result comes out negative. From 80 to 60: (60 − 80) ÷ 80 × 100 = −25%.
- Why isn’t going from 100 to 125 and back the same percentage?
- The starting value changes. 25 is 25% of 100 but only 20% of 125.
- What does a percentage change of −100% mean?
- The new value is 0.
- Can I average percentage changes?
- Not directly. A +50% year followed by a −50% year averages to 0%, but 100 → 150 → 75 is a 25% fall overall. Work from the actual values instead.
Related guides
- Change From Zero or NegativeWhy percentage change from zero is undefined, why a negative starting value can flip the sign, and how to report these changes honestly.
- Change vs. DifferenceWhen to measure from a starting value and when to compare two values side by side, the percent difference formula, and where percentage points fit.
Open the tool
Jump into Percentage Change Calculator when you are ready to process your files.
