Percentage change tells you how much something grew or shrank compared with before: sales this month vs last month, prices this year vs last year. Excel doesn’t have a special function for it. You just need one short formula.
The percentage change formula
=(New - Old) / OldWith the old value in B2 and the new value in C2:
=(C2-B2)/B2Then format the cell as a percentage: Home → %, or press Ctrl + Shift + %.
| Month | Last year (B) | This year (C) | Change (D) |
|---|---|---|---|
| Jan | 8,000 | 10,000 | 25% |
| Feb | 9,500 | 8,550 | -10% |
| Mar | 12,000 | 12,000 | 0% |
A positive result is an increase and a negative result is a decrease.
Don’t forget the brackets. =C2-B2/B2 divides first, then subtracts, and gives a completely wrong answer.
An equivalent formula some people prefer is =C2/B2-1. It gives the same result.
Avoid #DIV/0! when the old value is zero or blank
If the old value is 0 or empty, Excel can’t divide by it. Show a blank instead:
=IF(B2=0, "", (C2-B2)/B2)Or use IFERROR to catch any error:
=IFERROR((C2-B2)/B2, "")Show increases and decreases in colour
- Select the percentage column.
- Press Ctrl + 1 to open Format Cells.
- Choose Custom and type:
[Color10]+0.0%;[Red]-0.0%;0.0%
Increases now show in green with a plus sign, and decreases in red. For arrows or icon sets, use conditional formatting; see our conditional formatting examples.
Percentage of a total
To find what share each item is of the total, divide by the total and lock the total cell with $ signs:
=B2/$B$10Format as percentage, then copy down. All the results add up to 100%.
Increase or decrease a number by a percentage
Add 15% to a price in B2:
=B2*(1+15%)Remove 15% (for example, a discount):
=B2*(1-15%)If the percentage is in a cell, say E1, use =B2*(1+$E$1) so you can change it in one place.
Find the original price before a percentage was added
If a price of 115 already includes 15% tax, the original price is:
=B2/(1+15%)A common mistake is subtracting 15% from 115, which gives 97.75 instead of the correct 100.
Percentage change vs percentage point change
If a conversion rate goes from 4% to 5%, that’s a 1 percentage point increase, but a 25% increase in the rate. Both are correct; just be clear which one you mean in reports.
Quick formula reference
| Task | Formula |
|---|---|
| Percentage change | =(C2-B2)/B2 |
| Percentage of total | =B2/$B$10 |
| Add a percentage | =B2*(1+15%) |
| Subtract a percentage | =B2*(1-15%) |
| Remove an included percentage | =B2/(1+15%) |
Building a monthly report? Pair these formulas with a chart in a simple Excel dashboard.