Percent Change in Excel Formula: Cell Examples & Edge Cases

If you have two numbers in an Excel worksheet but are unsure which formula shows the real percentage change, the key issue is usually the starting value, cell references, or percentage formatting. This guide shows how to calculate percent change in Excel correctly, format the result, handle increases and decreases, and avoid errors such as #DIV/0! or incorrect percentage displays.

The Excel formula for percent change is (New Value - Old Value) / Old Value. In a worksheet, if the old value is in cell A2 and the new value is in B2, enter =(B2-A2)/A2. Excel returns a decimal result, such as 0.25, which becomes 25% when the cell is formatted as a percentage.

Percent change formula in Excel with cell examples

Percent change measures how much a value has increased or decreased compared with its original value. The basic formula uses the old value as the reference point because the question being answered is usually "how much did the value move from where it started?"

The standard formula is:

Percent Change = (New Value - Old Value) / Old Value

In Excel, this becomes:

=(New_Value-Old_Value)/Old_Value

For example, if a product’s sales increase from 100 to 120:

=(120-100)/100

The calculation is:

20/100 = 0.20

After percentage formatting, Excel displays this as 20%, meaning the new value is 20% higher than the original value.

The same calculation can be written in another equivalent form:

=(New Value / Old Value)-1

Using the same numbers:

=(120/100)-1

=1.2-1

=0.2

Both formulas produce the same result. The first version is usually easier to understand because it directly shows the amount of change divided by the starting amount.

A common worksheet layout uses separate columns for the original value and the new value:

The second row returns:

=(200-250)/250

=-50/250

=-0.20

After percentage formatting, Excel displays -20%, meaning the value decreased by 20%.

Writing and formatting percent change formulas in worksheets

A percent change formula works like any other Excel worksheet formula: it uses cell references, arithmetic operators, and formatting rules. The calculation itself creates a decimal value; formatting controls how that value appears to the reader.

To calculate percentage change between two cells:

1. Enter the original value in one cell, such as A2.
2. Enter the new value in another cell, such as B2.
3. Select the result cell and type =(B2-A2)/A2.
4. Press Enter to calculate the decimal result.
5. Apply percentage formatting so Excel displays the result as a percentage.

For example, with A2 = 80 and B2 = 100:

=(B2-A2)/A2

=(100-80)/80

=20/80

=0.25

The displayed result becomes 25% after percentage formatting.

Excel does not require a special percent change function. The calculation uses normal worksheet formulas and cell references.

A common point of confusion in spreadsheet work is mixing up the stored decimal value with the displayed percentage. Excel stores 0.25 as the underlying result, while percentage formatting displays that same value as 25%.

To format the result as a percentage:

1. Select the formula result cell.
2. Open the Home tab.
3. Choose the % button in the Number group.
4. Alternatively, use the Ctrl+Shift+5 shortcut to apply percentage formatting.

You can also choose a specific percentage format through the Format Cells options if you need a certain number of decimal places.

A frequent mistake is adding *100 to the formula and then applying percentage formatting. These are two different ways of displaying percentages, and using both changes the result incorrectly.

For example:

=((120-100)/100)*100

returns:

20

If that cell is formatted as a percentage, Excel displays 2000% instead of 20% because the value was already multiplied by 100 before formatting.

Use one method:

• Use =(B2-A2)/A2 and apply Percentage formatting.
• Or use =((B2-A2)/A2)*100 when you need a plain number representing the percent value.

Do not combine both approaches.

Calculating increases, decreases, and growth rates

Excel percentage increase and percentage decrease formulas are variations of the same percent change calculation. The difference is how the result is interpreted.

For an increase, use:

=(New Value-Original Value)/Original Value

Example: a price changes from 50 to 65.

=(65-50)/50

=15/50

=0.30

The result is 30%, so the new price is 30% higher than the original price.

For a decrease, use the same structure:

=(New Value-Original Value)/Original Value

Example: a budget changes from 500 to 400.

=(400-500)/500

=-100/500

=-0.20

The result is -20%, indicating a 20% decrease.

An Excel growth rate formula follows the same pattern when comparing two periods. For example, a month-over-month growth calculation compares the current month with the previous month:

=(Current Period-Previous Period)/Previous Period

The important part is identifying which value represents the baseline. The denominator should usually be the original or earlier value being compared against.

Applying percent changes to updated values

Sometimes the goal is not to measure a change but to create a new value after applying a known percentage increase or decrease.

For a percentage increase, use:

=Original Value*(1+Increase Rate)

Example: increase 100 by 20%:

=100*(1+20%)

=100*1.2

=120

For a percentage decrease, use:

=Original Value*(1-Decrease Rate)

Example: reduce 100 by 20%:

=100*(1-20%)

=100*0.8

=80

For a 3% increase, the formula is:

=Original Value*(1+3%)

If the original value is in A2, use:

=A2*(1+3%)

This approach changes the value itself. It is different from calculating the percent change between two existing values.

Fixing errors in percent change calculations

Percent change formulas usually fail because the original value cannot be used as a denominator or because one of the referenced cells does not contain a usable number. The correct fix depends on the cause.

In practical spreadsheet work, the easy-to-miss step is identifying whether the formula is mathematically undefined or whether the worksheet contains invalid input. A blank result, a warning label, or a replacement value each communicates something different to anyone reading the spreadsheet.

The #DIV/0! error appears when a formula attempts to divide by zero. In percent change calculations, this usually happens when the original value is 0.

For example:

=(50-0)/0

has no defined percentage change because there is no starting quantity to compare against.

An IF() formula lets you decide what Excel should show instead:

=IF(A2=0,"N/A",(B2-A2)/A2)

This keeps the worksheet readable by replacing the error with a label.

The #VALUE! error has a different cause. It occurs when Excel cannot perform the calculation because a referenced value is not the expected type, such as text entered where a number should be.

For example, if A2 contains the text January instead of a numeric starting value, this formula cannot calculate correctly:

=(B2-A2)/A2

Check the referenced cells and replace text entries with numeric values before changing the formula.

Reading negative percent change results correctly

A negative percent change is not automatically a formula error. In a normal positive-value comparison, it means the new value is lower than the original value.

For example:

Old value: 500
New value: 400

Formula:

=(400-500)/500

Result:

-20%

The worksheet meaning is a 20% decrease.

The interpretation becomes less obvious when the original value is zero or negative. The formula depends on the baseline, and a negative baseline can make the sign difficult to explain in everyday language.

A practical decision rule is:

• If the original value is positive, a negative result usually means a decrease.
• If the original value is zero, percent change is undefined and should usually be labeled instead of calculated.
• If the original value is negative, show the calculation and add context rather than relying only on "increase" or "decrease" wording.

For example, a loss changing from -100 to 50 is a movement toward a positive result, but the basic formula:

=(50-(-100))/(-100)

=150/-100

=-1.5

produces -150%.

The negative sign here does not communicate a normal decrease. It reflects the negative starting value. For financial or performance reports, many analysts use a separate label such as "loss converted to profit" rather than describing this as a simple percentage decrease.

Handling negative original values

Negative starting values require more care because the original value changes the meaning of the ratio. A loss-to-profit transition is a common example where a standard percent change formula can produce a mathematically correct but confusing result.

If a worksheet tracks values that can cross zero, such as profits, losses, credits, or deficits, consider adding a condition that flags negative baselines.

For example:

=IF(A2<=0,"Review baseline",(B2-A2)/A2)

This does not claim the change cannot be calculated. It tells the spreadsheet reader that the result needs interpretation.

Another option is using the absolute value of the original amount as the comparison base:

=(B2-A2)/ABS(A2)

For a change from -100 to -50:

=(-50-(-100))/ABS(-100)

=50/100

=50%

This shows that the loss amount improved by 50% when measured against the size of the original loss. The appropriate method depends on whether the goal is mathematical comparison, financial reporting, or communication with non-technical readers.

Calculating percent change across multiple periods

A single percent change formula becomes more useful when it is applied across a series of periods. Common examples include month-over-month changes, year-over-year growth rates, and sequential sales comparisons.

Suppose a worksheet contains monthly sales:

The formula always compares the current row with the previous row. When copied downward, Excel adjusts the cell references automatically.

Use this workflow:

• Enter the first comparison formula as =(C3-C2)/C2 when adjacent periods are stored in column C.
• Copy the formula down with the fill handle so each row compares its own neighboring periods.
• Check that the references move from one row to the next instead of staying fixed on the first period.
• Apply percentage formatting to review month-over-month or year-over-year changes.

For example, if monthly values are in cells B2:B6, the formula in C3 can be dragged down:

=(B3-B2)/B2

The next rows automatically become:

=(B4-B3)/B3

=(B5-B4)/B4

This approach avoids manually rewriting formulas for every period.

Percent change versus percentage points in Excel

Percent change and percentage points are often confused because both involve percentages, but they answer different questions. Percent change measures relative movement from a starting value, while percentage points measure the direct difference between two percentage values.

The choice depends on the question being asked. If a report says an interest rate moved from 10% to 12%, saying it increased by 2 percentage points is often clearer because the values are already rates.

If the question is how much larger the new rate is compared with the old rate, use percent change.

Examples using percentage-based values

Consider a worksheet containing a conversion rate that moves from 10% to 12%.

1. Subtract the old rate from the new rate: 12%-10%=2 percentage points.
2. Divide the difference by the old rate: (12%-10%)/10%=0.20.
3. Format the result as a percentage: 0.20=20%.

The result is two different statements:

• The rate increased by 2 percentage points.
• The rate increased by 20% relative to its original value.

Both calculations are correct, but they communicate different information.

Common formula interpretation mistakes

A common mistake occurs when a percentage value is treated as both a formatted percentage and a multiplied number. Excel already understands that 20% represents 0.20 internally.

For example:

=(120-100)/100

returns:

0.2

Percentage formatting displays:

20%

Adding *100 changes the stored result:

=((120-100)/100)*100

returns:

20

If the cell is then formatted as a percentage, the displayed value becomes 2000%.

Use percentage formatting when the worksheet should display a percent. Use multiplication by 100 only when the output needs to be a plain numeric percent value for another purpose.

Check your formulas today by entering an old value and a new value in two cells, typing =(new-old)/old with your own cell references, and applying the % button so the worksheet displays the change correctly instead of a confusing decimal.

FAQ

Is there an Excel formula for percent change?

Yes. The Excel formula for percent change is (New Value - Old Value) / Old Value. In a worksheet, if the old value is in cell A2 and the new value is in B2, you would enter =(B2-A2)/A2. Excel returns a decimal result that you can format as a percentage using the % button on the Home tab or the Ctrl+Shift+5 shortcut.

What is the formula for percent change in Excel?

The formula for percent change in Excel is (New Value - Old Value) / Old Value. An equivalent alternative is (New Value / Old Value) - 1. Both produce the same result. For example, =(120-100)/100 and =(120/100)-1 both return 0.2, which displays as 20% after percentage formatting.

How do I calculate percentage change between two numbers in Excel?

Enter the original value in one cell (e.g., A2) and the new value in another cell (e.g., B2). In the result cell, type =(B2-A2)/A2 and press Enter. Then apply percentage formatting by selecting the cell and clicking the % button in the Number group on the Home tab, or use the Ctrl+Shift+5 keyboard shortcut.

How do I format the result as a percentage in Excel?

Select the cell containing your percent change formula result. On the Home tab, click the % button in the Number group. Alternatively, press Ctrl+Shift+5 to apply percentage formatting instantly. You can also open Format Cells to specify the number of decimal places if you need more precision in the displayed percentage.

How do I prevent division by zero in Excel formulas?

Use an IF() function to check if the original value is zero before dividing. For example, =IF(A2=0,"N/A",(B2-A2)/A2) returns "N/A" when the old value in A2 is zero, preventing the #DIV/0! error. You can also use =IFERROR((B2-A2)/A2,0) to return 0 instead of an error when any calculation issue occurs.