How to Calculate Percentages in Excel (Formulas + Examples)

Excel makes percentage calculations quick once you know which formula to use. The exact formula depends on what you want to find: a percentage of a total, a percentage change, or a percent increase or decrease.

1. How to calculate a percentage of a total in Excel

If the part is in B2 and the total is in C2, use:

=B2/C2

Then format the result cell as Percentage.

Example: if B2 = 25 and C2 = 200, Excel returns 0.125, which displays as 12.5% after formatting.

2. How to calculate percentage increase in Excel

If the old value is in A2 and the new value is in B2, use:

=(B2-A2)/A2

Format the result as Percentage.

Example: from 80 to 100 gives =(100-80)/80 which equals 25%.

3. How to calculate percentage decrease in Excel

Use the same change formula:

=(B2-A2)/A2

If the result is negative, it means the value decreased.

Example: from 200 to 150 gives =(150-200)/200 which equals -25%.

4. How to add or subtract a percentage in Excel

To increase a number in A2 by 15%, use:

=A2*(1+15%)

To decrease it by 15%, use:

=A2*(1-15%)

Example: if A2 = 200, increasing by 15% gives 230 and decreasing by 15% gives 170.

5. How to format percentages in Excel

• Select the result cell.
• Go to Home > Number.
• Click the % button.
• Use Increase Decimal if you want more precision.

Important: if you type 25 into a percentage-formatted cell, Excel shows 2500%. To show twenty five percent, type 25% or 0.25.

Common Excel percentage mistakes

• Forgetting to format the result as a percentage.
• Dividing by the wrong cell when calculating percentage change.
• Typing whole numbers into percentage cells without the percent sign.

Need a faster option?

If you want to double-check the result outside Excel, use our percentage calculator.

FAQ

What is the Excel formula for percentage?

For a percentage of a total, use =part/total and format the result as Percentage.

How do I calculate percentage change in Excel?

Use =(new-old)/old and format the result as Percentage.

Why does Excel show 2500% instead of 25%?

Because Excel stores percentages as decimals. To display 25%, enter 25% or 0.25, not 25.