How do I calculate percentage change between two values?
Percentage change is (new value minus old value) divided by the old value, formatted as a percentage: =(B2-A2)/A2. Format the result cell as a percentage so it displays correctly, for example 14% instead of 0.14.
Formula (Excel and Google Sheets)
=(B2-A2)/A2The formula compares how much a number changed relative to where it started. If A2 (the old value) is 100 and B2 (the new value) is 114, the result is (114-100)/100 = 0.14, which displays as 14% once the cell is formatted as a percentage. A negative result means the new value is lower than the old one.
The most common mistake is dividing by the new value instead of the old one, which quietly produces the wrong percentage, or forgetting to format the cell as a percentage, which shows 0.14 instead of 14% and is easy to misread in a report.
Step by step
- 1
Identify the old and new values
Old value is what you are comparing from; new value is what you are comparing to.
- 2
Subtract old from new
This gives the raw difference, which can be negative if the value decreased.
- 3
Divide by the old value
Always divide by the OLD value, not the new one, since percentage change is measured relative to the starting point.
- 4
Format the result as a percentage
Apply percentage formatting to the cell so 0.14 displays as 14% instead of a decimal.
Common questions
Why is my percentage change showing as a decimal like 0.14?
The cell needs percentage formatting applied. The underlying math is correct; only the display format is missing.
What if the old value is zero?
Percentage change is undefined when the starting value is zero (division by zero). Handle it with an IF check, e.g. =IF(A2=0,"n/a",(B2-A2)/A2).
Related formulas
How to Use SUMIF and SUMIFS in Excel and Google Sheets
RelatedHow to Use XLOOKUP in Excel and Google Sheets
RelatedHow to Format Text and Dates with the TEXT Formula
From the blogHow to Make Sense of Your Spreadsheet Data Without Being an Analyst
Want a formula written for your exact spreadsheet, not a generic example?
Try the free formula generator