The Excel percentage change formula is =(new-old)/old. In a worksheet, that usually looks like =(B2-A2)/A2, where A2 contains the starting value and B2 contains the new value. Format the result cell as Percentage, and Excel will show the change in the way most people expect: 25%, -20%, 0%, and so on.
This formula is the one to reach for when you want growth, decline, or movement relative to a baseline. A bigger raw gap does not always mean a bigger percentage change, because the denominator matters. For example, a jump from 10 to 15 is a 50% increase, while a jump from 100 to 105 is only 5%.
If you need the opposite operation, use the Excel subtraction formula. If you are averaging a column of percentages rather than measuring change, use Excel average formula percentage.
What the percentage change formula does in Excel
The percentage change formula tells you how large a change is relative to the original value. That makes it a much better comparison tool than simple subtraction when the starting values are different sizes. A 20-unit increase on a 100-unit baseline is much smaller than a 20-unit increase on a 40-unit baseline, and the percentage change formula makes that difference obvious.
The structure is simple:
=(new-old)/oldOr, if you are using cell references:
=(B2-A2)/A2The result is a decimal until you format the cell. So 0.25 is not wrong; it just means the cell still needs percentage formatting.
A quick way to think about the formula is:
- New minus old = how much the value moved
- Divide by old = how large that move is relative to the starting point
- Format as Percentage = how Excel should display the answer
If the result is positive, the value increased. If it is negative, the value decreased. If it is zero, nothing changed.
The exact Excel formula to use
The best default formula is =(B2-A2)/A2 when A2 holds the old value and B2 holds the new one. That version is easy to copy down a column, easy to audit, and easy to explain to someone else later.
If you are entering it by hand, the workflow is:
- Put the old value in one column.
- Put the new value in the next column.
- Enter
=(new-old)/oldin the result column. - Format the result cell as Percentage.
- Copy the formula down if you have more rows.
Here is a small example:
| Old value | New value | Formula | Result |
|---|---|---|---|
| 100 | 125 | =(B2-A2)/A2 | 25% |
| 100 | 80 | =(B3-A3)/A3 | -20% |
| 50 | 75 | =(B4-A4)/A4 | 50% |
When the numbers are copied down a sheet, absolute references can help. For example, if all of your rows compare against one fixed baseline in A1, use =(B2-$A$1)/$A$1. The dollar signs lock the baseline so the reference does not shift as you fill the formula downward.
Percentage increase vs percentage decrease
The same formula handles both increase and decrease. You do not need separate formulas for growth and decline. If the new value is larger than the old value, the result is positive. If the new value is smaller, the result is negative.
That is one reason this formula is so useful in finance, sales, operations, and performance reporting. A manager can scan a column of percentage change values and immediately see whether each row moved up or down.
Examples:
- 100 → 120 =
=(120-100)/100= 20% increase - 100 → 90 =
=(90-100)/100= -10% decrease - 200 → 150 =
=(150-200)/200= -25% decrease
If you want the result to show only the magnitude, you can wrap the formula in ABS(). For example, =ABS((B2-A2)/A2) returns 25% instead of -25%. That can be useful when you care about size more than direction, but it also hides whether the value rose or fell.
A good rule of thumb: keep the sign when you need reporting clarity, and remove it only when the sign is irrelevant.
Percentage change vs percentage difference
Percentage change uses the original value as the baseline. Percentage difference is more symmetric: it compares two values without treating one as the permanent starting point.
That distinction matters when neither value is clearly the baseline. If you are comparing two similar prices, two test scores, or two measurements that are just being contrasted, percentage difference may be the better term.
A common percentage difference formula is:
=ABS(B2-A2)/AVERAGE(A2,B2)With 90 and 110, the difference is 20 and the average is 100, so the percentage difference is 20%.
Use percentage change when you are tracking movement from one known starting point to a new value. Use percentage difference when you want a neutral comparison between two values.
If your report is about a metric growing from one period to the next, percentage change is usually the right choice.
How to format percentage change correctly in Excel
Excel often shows the raw decimal first, and that can look confusing if you expect to see a percent sign right away. The fix is to format the result cell as Percentage after entering the formula.
That matters because Excel stores percentages as decimals. Microsoft’s support docs note that 10% is stored as 0.1, and percentage formatting displays that underlying decimal as a percentage. So a result of 0.25 is the same as 25%; the cell just needs the right number format.
Sourced stat block
| Source | Fact | Why it matters |
|---|---|---|
| Microsoft Support | 10% is stored as 0.1, and percentage formatting displays the decimal as a percent. | Enter the formula first, then format the result cell as Percentage so the output reads as 25%, not 0.25. |
Source: Microsoft Support — Format numbers as percentages in Excel
A few formatting tips make the result easier to read:
- Use Percentage with one or two decimal places if you need precision.
- Use a custom number format if your report style requires a specific number of decimals.
- Keep the formula cell separate from the input cells so the logic is easy to audit.
- If you want to highlight gains and losses, add conditional formatting so positive values appear green and negative values appear red.
Common mistakes to avoid
The percentage change formula is simple, but a few common mistakes can make the result look wrong.
Dividing by the new value instead of the old value
The denominator should be the original value. If you divide by the new value, the result answers a different question and the percentage will not match your expectation.
Forgetting to format the result as a percentage
If Excel shows 0.25, that usually means the math is correct but the cell still uses a General or Number format. Apply Percentage formatting and the display changes to 25%.
Using a zero baseline without a fallback
If the old value is 0, percentage change is undefined because you cannot divide by zero. In that case, use a guard like:
=IF(A2=0,"",(B2-A2)/A2)That leaves the result blank when the baseline is zero. You could also return "N/A" if that works better for your report.
Losing the sign when direction matters
ABS() removes the minus sign. That is fine for magnitude-only comparisons, but it is a mistake if you need to know whether the value increased or decreased.
Mixing text and numbers
If Excel stores a value as text, the formula may fail or return the wrong result. Convert text-looking numbers before calculating, especially if the data came from copy/paste or an export.
When to use this formula in real work
The percentage change formula is the right tool when the question is, “How much did this move relative to where it started?” That comes up constantly in budgeting, pricing, sales reporting, inventory tracking, and KPI dashboards.
A few practical examples:
- Revenue grew from 80,000 to 92,000.
- Units sold fell from 1,200 to 1,050.
- A price changed from 49.99 to 59.99.
- A conversion rate moved from 2.4% to 3.1%.
In all of those cases, percentage change gives a clearer answer than subtraction alone. A 12,000 revenue increase and a 12,000 revenue increase are not equally meaningful if one started at 30,000 and the other started at 300,000.
If you are building a worksheet that combines change, average, and comparison logic, pair this post with Excel average formula percentage and Excel subtraction formula.
FAQ
How do I calculate percentage change in Excel?
Use =(new-old)/old. With 100 in the old-value cell and 125 in the new-value cell, the result is 25%. With 100 and 80, the result is -20%. The formula works for both increases and decreases.
How do I calculate percentage increase in Excel?
Use the same formula: =(new-old)/old. If the value goes from 100 to 150, the change is 50%. You do not need a separate increase formula because the positive result already tells you the value went up.
How do I calculate percentage decrease in Excel?
Use the same formula: =(new-old)/old. If the value goes from 100 to 75, the result is -25%. The minus sign is useful because it shows a decrease and the amount of the decrease at the same time.
What is the difference between percentage change and percentage difference?
Percentage change uses the old value as the baseline. Percentage difference is more symmetric and often uses the average of the two values. For example, 90 and 110 have a 20-point gap, but the percent answer depends on whether you are comparing from 90 to 110 or using a shared baseline.
Why does Excel show 0.25 instead of 25%?
Because Excel stores 25% as 0.25. The formula output is correct; the cell just needs Percentage formatting. Once formatted, 0.25 displays as 25% and becomes easier to read in reports.
