How to Calculate Percentage Change in Excel

To calculate percentage change in Excel, subtract the old value from the new value, then divide that result by the old value. If the old value is in B2 and the new value is in C2, use this formula:

=(C2-B2)/B2

Then format the result as a percentage. For example, if sales increased from 8000 to 9200, Excel returns 0.15 before formatting, which displays as 15% after you apply Percentage format.

The Percentage Change Formula in Excel

The standard percentage change formula is:

=(new_value-old_value)/old_value

In worksheet cell references, that usually looks like this:

=(C2-B2)/B2

Use this when:

• B2 contains the old or starting value,
• C2 contains the new or ending value,
• you want the change relative to the old value.

The formula works because the numerator finds the amount of change, and the denominator compares that change to the original baseline. If you need a refresher on that first part of the formula, the guide on how to subtract in Excel explains the basic new minus old pattern.

Set Up the Example Data

Use a simple table like this:

The sales row shows an increase. The expenses row shows a decrease. The leads row shows another increase.

Excel stores each result as a decimal value. The 15% result is really 0.15 with percentage formatting applied.

Calculate Percentage Change Between Two Cells

Suppose the old value is in B2 and the new value is in C2.

Enter this formula in D2:

=(C2-B2)/B2

Then copy the formula down for the rest of your rows.

For the sales example:

=(9200-8000)/8000

That becomes:

=1200/8000

The result is:

0.15

After percentage formatting, 0.15 displays as 15%.

Use the Shorter Version

This formula gives the same result:

=C2/B2-1

It works because dividing the new value by the old value tells you how large the new value is compared with the baseline.

For example:

=9200/8000-1

The result is:

0.15

Both versions are correct. For beginners, =(C2-B2)/B2 is often easier to understand because it shows the change first.

Format the Result as a Percentage

If Excel shows 0.15, the formula is probably correct. You just need to format the result.

To format the result as a percentage:

1. Select the formula cells.
2. Go to the Home tab.
3. In the Number group, choose Percent Style.
4. Use Increase Decimal or Decrease Decimal if you want more or fewer decimal places.

Microsoft's Calculate percentages guide shows the same core idea: Excel calculates a decimal first, then percentage formatting changes how that decimal is displayed.

Percentage formatting does not change the actual stored value. It changes how Excel displays the number in the cell.

Calculate Percentage Increase

A percentage increase is just a positive percentage change.

If revenue moved from 8000 to 9200, use:

=(9200-8000)/8000

The result is:

15%

With cell references:

=(C2-B2)/B2

Use this pattern for sales growth, traffic growth, lead growth, score improvement, or any other metric where the new value is higher than the old value.

Calculate Percentage Decrease

A percentage decrease uses the same formula. The result is negative because the new value is smaller than the old value.

If expenses moved from 5000 to 4250, use:

=(4250-5000)/5000

The result is:

-15%

With cell references:

=(C2-B2)/B2

You do not need a separate formula for decreases. Excel returns a negative percentage automatically when the new value is lower.

Avoid #DIV/0! When the Old Value Is Zero

Percentage change needs a baseline. If the old value is zero, Excel cannot divide by it, so the basic formula returns #DIV/0!.

Use IF to handle that case:

=IF(B2=0,"",(C2-B2)/B2)

This formula returns a blank cell when the old value is zero. Otherwise, it calculates the percentage change.

If you want the worksheet to explain the problem instead of staying blank, use:

=IF(B2=0,"No baseline",(C2-B2)/B2)

That is often better in a shared report because it tells the reader why there is no percentage change result.

Percent Change vs Percentage Difference

Percent change and percentage difference sound similar, but they answer different questions.

Use percent change when one value clearly comes before the other:

=(new_value-old_value)/old_value

That is the right choice for month-over-month sales, before-and-after measurements, or old-vs-new report values.

Percentage difference is usually used when neither number is clearly the baseline. It compares the absolute difference to the average of the two numbers:

=ABS(C2-B2)/AVERAGE(B2,C2)

For most business reports, trend reports, and before-and-after worksheets, percentage change is the formula you want. If you are analyzing averages more broadly, the AVERAGE function in Excel guide is a good next step.

Common Mistakes

Using the new value as the denominator

For percentage change, divide by the old value:

=(C2-B2)/B2

Do not divide by the new value unless you are intentionally answering a different question.

Forgetting to format as a percentage

If the result is 0.2, that means 20%. Apply Percent Style to display it as a percentage.

Treating zero as a normal baseline

If the old value is zero, there is no meaningful percentage change from zero using the normal formula. Use an IF formula to return a blank or a clear label.

Reversing old and new values

This formula compares the new value to the old value:

=(C2-B2)/B2

If you accidentally reverse the cells, the sign and percentage will change.

FAQ

What is the percentage change formula in Excel?

The percentage change formula in Excel is:

=(new_value-old_value)/old_value

With the old value in B2 and the new value in C2, use:

=(C2-B2)/B2

Why does Excel show 0.15 instead of 15%?

Excel stores percentages as decimal values. 0.15 is the same value as 15%. Apply Percentage format to show the result as a percentage.

Is percent change new minus old or old minus new?

Use new minus old:

=(new_value-old_value)/old_value

That gives a positive result when the value increased and a negative result when the value decreased.

Can I use new divided by old minus 1?

Yes. This formula is equivalent:

=new_value/old_value-1

With cell references:

=C2/B2-1

Use whichever version is easier for you to read.

What if the old value is zero?

If the old value is zero, the normal percent change formula returns #DIV/0! because Excel cannot divide by zero. Use:

=IF(B2=0,"",(C2-B2)/B2)

or:

=IF(B2=0,"No baseline",(C2-B2)/B2)

How do I show negative percentage changes?

Use the same formula and format the result as a percentage. Excel will show a negative percentage when the new value is smaller than the old value.

If you later want to work backward from a target percentage to the input needed, Goal Seek in Excel can help with that kind of what-if calculation.