Calculating your percentage change is straightforward once you know the Percentage Change formula and what each input means. This guide explains the method in plain language, walks through a manual calculation, and gives worked examples you can follow — then you can do it instantly with the Percentage Change Calculator.
What is Percentage Change?
The Percentage Change calculation tells you your percentage change from a few simple inputs. The figure you are solving for here is the percentage change, expressed in percent.
The Percentage Change formula
The core formula is:
Percentage change = (New value - Original value) ÷ Original value × 100Here is what each input means:
- Original value — a number. Example: 50.
- New value — a number. Example: 75.
How to calculate it step by step
- Write down the original value (for example, 50).
- Write down the new value (for example, 75).
- Apply the formula above to get your percentage change.
- Double-check the result with the Percentage Change Calculator.
Worked examples
Example 1
| Input / Output | Value |
|---|---|
| Original value | 50 |
| New value | 75 |
| Percentage change | 50.00% |
| Absolute change | 25.00 |
With original value of 50 and new value of 75, the percentage change works out to 50.00%.
Example 2
With original value of 100 and new value of 75, the percentage change works out to -25.00%.
| Result | Value |
|---|---|
| Percentage change | -25.00% |
| Absolute change | -25.00 |
Example 3
With original value of 25 and new value of 75, the percentage change works out to 200.00%.
| Result | Value |
|---|---|
| Percentage change | 200.00% |
| Absolute change | 50.00 |
Tips for an accurate result
- Keep your units consistent — mixing, say, months with years or grams with kilograms is the most common source of error.
- Round only at the very end. Rounding inputs early can shift the final answer noticeably.
- Re-run the numbers whenever an input changes, rather than estimating from an old result.
Prefer not to do the maths by hand? — the Percentage Change Calculator does it instantly, for free, with the formula and a worked example built in.
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