Use Excel’s percentage change formula to measure how much a value increased or decreased relative to its starting value.
The calculation is simple, but choosing the correct baseline and handling zero or negative values can change how you interpret the result.
What is the Excel percentage change formula?
Percentage change compares a new value with an original value.
Subtract the original value from the new value, then divide the difference by the original value:
=(new_value-original_value)/original_value
For example, if the original value is in cell A2 and the new value is in B2, enter this in C2:
=(B2-A2)/A2
If A2 contains 80 and B2 contains 100, the calculation is (100 − 80) ÷ 80, or 0.25.
Format C2 as a percentage to display 25%.
A positive result means an increase; a negative result means a decrease.
Use the original value as the denominator.
Dividing by the new value instead would answer a different question and produce a different percentage.
How to calculate percentage change in a column
Suppose a worksheet tracks monthly sales, with the earlier month in column B and the later month in column C.
Put the formula in D2:
=(C2-B2)/B2
Then fill or copy the formula down the column for the other rows.
Excel adjusts the relative references automatically, so the next row uses C3 and B3.
Format the result cells as percentages using the Home tab’s Number group or the percentage format shortcut, then choose the number of decimal places you need.
Here is a small example:
- Original sales: 250
- New sales: 300
- Formula result: 0.2
- Percentage change: 20% increase
For a decrease from 250 to 200, the same formula returns -0.2, which displays as -20%.
You can label the column “Percentage change” and use conditional formatting to distinguish positive and negative results, while keeping the displayed sign visible.
How do you calculate percentage change when the starting value is zero?
The standard formula divides by the original value, so it cannot return a finite percentage when that value is zero.
For example, =(B2-A2)/A2 returns a division-by-zero error if A2 is 0.
There is no meaningful percentage increase from zero under the usual definition, because the baseline needed for comparison does not exist.
If your report should display a label instead of an error, use an IF formula to handle that case explicitly:
=IF(A2=0,"N/A",(B2-A2)/A2)
This returns “N/A” when the original value is zero and calculates the percentage change otherwise.
Because the formula can return either text or a number, format the result column as General or use a custom display approach suitable for your report.
Another option is to leave the result blank when there is no valid baseline:
=IF(A2=0,"",(B2-A2)/A2)
Choose the label that matches your reporting convention.
Do not silently replace the starting zero with 1 or another value; that changes the calculation rather than resolving the missing baseline.
How does the formula behave with negative values?
Mathematically, the standard formula still works with negative starting values, but the resulting sign may not match the everyday meaning of “up” or “down.” For instance, changing from -100 to -50 gives =(-50-(-100))/-100, or -50%.
The value moved upward toward zero, yet the formula shows a negative percentage change because the original denominator is negative.
For financial or operational reports involving losses, debts, temperatures below zero, or other signed values, decide what the percentage should communicate before presenting it.
You may want to report the absolute difference, explain the movement in words, or use a business-specific convention.
Avoid interpreting the sign mechanically when the baseline is negative.
Percentage change versus percentage difference
Percentage change uses a specific starting value as its baseline.
It answers, “How much did this value change compared with where it started?” Percentage difference is often used to compare two values when neither is designated as the original.
One common version divides the absolute difference by the average of the two values:
=ABS(B2-A2)/AVERAGE(A2,B2)
For values 80 and 100, this formula gives about 22.22%, while percentage change from 80 to 100 is 25%.
These are different measures.
Use percentage change for before-and-after comparisons, such as year-over-year revenue.
Use percentage difference only when the comparison is symmetric and no value serves as the baseline.
Common mistakes and formula checks
- Reversing the subtraction:
=(A2-B2)/A2reverses the direction of the result.
Put the new value first and subtract the original value. - Using the wrong denominator: Divide by the original value, not the new value or the difference.
- Multiplying and also applying percentage format: The formula should normally return a decimal such as 0.25.
Percentage formatting displays it as 25%.
If you multiply by 100 and then apply percentage format, Excel displays 2,500%. - Confusing percentage points with percent change: A rate rising from 10% to 12% increases by 2 percentage points, or 20% relative to its original rate.
- Ignoring blanks or text: Check that the input cells contain numeric values.
If a blank should count as zero in your analysis, make that rule explicit rather than relying on accidental cell behavior.
Excel and Google Sheets compatibility
The basic formula =(B2-A2)/A2 works in current desktop versions of Microsoft Excel, Excel for the web, and Google Sheets.
It uses standard arithmetic and cell references, so it does not require a newer function or a particular subscription.
The IF example also works in these spreadsheet applications.
In locales that use semicolons as function argument separators, enter the IF formula with semicolons instead of commas, for example =IF(A2=0;"N/A";(B2-A2)/A2).
If a formula is rejected, check the spreadsheet’s regional settings, argument separator, and whether the referenced cells contain numbers.
These formulas are suitable for ordinary worksheet ranges; when building a larger report, apply the same baseline rule consistently to every row.