How to Find a Percentage in Excel: Formulas and Examples

To find what percentage one value is of another, divide the part by the whole and format the result as a percentage. With the part in A2 and the whole in B2, enter =A2/B2 in C2; if A2 is 25 and B2 is 200, the result displays as 12.5% when C2 is percentage-formatted. Excel can also calculate a percentage of an amount and the percentage increase or decrease between two values.

The examples below use Excel for Microsoft 365 on Windows. The same formulas work in Excel for Mac and Excel for the web, although ribbon layout and some keyboard shortcuts can vary.

What You’ll Need

An Excel workbook with the relevant numbers entered in cells.
A clear idea of which value is the part and which is the whole, or which values are the original and new amounts.
For percentage change, a starting value that is not zero. A percentage change from zero cannot be calculated using the standard formula.

Step-by-Step

Choose the type of percentage you need. The most common calculation is a part as a percentage of a whole, such as the share of a target completed or the proportion of a budget spent. Other common tasks are finding a percentage of a number, such as a discount, and finding how much a value increased or decreased compared with its starting value. Decide which question your spreadsheet should answer before entering a formula.
Arrange the part and whole in separate cells. For example, put 18 items sold in A2 and a target of 24 items in B2. In C2, enter =A2/B2. The calculation is 18 divided by 24, or 0.75. Select C2, then choose Home > Number > Percent Style. The displayed result is 75%. This is the basic formula for finding a percentage: part divided by whole. Use cell references rather than typing the numbers into the formula so the result updates when either value changes.

Check that the number you call the whole really is the full amount you want to compare against. If you are calculating one department’s share of a company total, use the department amount as the part and the company total as the whole. Reversing those references gives a different answer: 24 divided by 18 is about 133.3%, not 75%.
Format the result as a percentage. Select the result cell or range, open the Home tab, and choose Percent Style in the Number group. Excel displays the decimal result multiplied by 100 and adds a percent sign. For example, the underlying result 0.75 displays as 75%. You can adjust the displayed precision using Increase Decimal or Decrease Decimal in the same Number group. A result of 12.5% is often more useful than 13% when small differences matter, while a whole number may be easier to read in a summary.

Formatting changes how a value appears, not the underlying calculation. Excel still stores 75% as 0.75, so you can use the result in other formulas. You usually should not multiply a part-to-whole formula by 100 and also apply percentage formatting: that would display 75 as 7,500%.
Calculate a percentage of an amount. Suppose A2 contains a price of 80 and B2 contains a rate entered as 15%. With those values in A2 and B2, enter =A2*B2 in C2. The result is 12, which is 15% of 80. Format C2 as Currency if you want to show it as a money amount, such as $12.00, rather than as a percentage. This multiplication method also works for quantities, tax estimates, discounts, and other simple percentage amounts.

If you want the amount after a discount rather than the discount amount, use the price multiplied by one minus the rate. With the original price in A2 and the discount rate in B2, enter =A2*(1-B2) in C2. For an 80 price and a 15% discount, the result is 68. This calculates the remaining amount; it does not calculate taxes, fees, or any other adjustments that might apply in a real transaction.
Calculate a percentage increase or decrease. Put the original value in A2 and the new value in B2. In C2, enter =(B2-A2)/A2. If the original value is 100 and the new value is 125, the formula returns 0.25, which displays as a 25% increase when C2 is formatted as a percentage. If the new value is 80, the result is -20%, indicating a decrease. The sign is useful: a positive result means an increase and a negative result means a decrease.

The original value belongs in the denominator because the question is how large the change is relative to where you started. Dividing the change by the new value answers a different question and can produce a misleading comparison. If the original value is zero, Excel returns a division-by-zero error; use a note such as Not applicable rather than trying to interpret an undefined percentage change.
Apply the same calculation to more rows. If each row has a part in column B and a shared total in B10, put the formula in C2 and fill it down. With the first part in B2 and the fixed total in B10, enter =B2/$B$10 in C2. If B2 is 30 and B10 is 120, C2 displays 25%. The dollar signs keep the total reference fixed when you copy the formula down, while the part reference changes to B3, B4, and so on.

To fill down, select the formula cell and drag its small fill handle at the lower-right corner of the selection down the column. You can also copy the cell and paste it into the destination cells. Check a few rows after filling to confirm that each formula points to the correct part and that the denominator remains the intended total.
Compare two percentages when useful. A change from 25% to 30% is an increase of 5 percentage points. It is also a 20% relative increase because the difference, 5%, is one-fifth of the original 25%. These are different ways to describe the change. If A2 contains 25% and B2 contains 30%, enter =B2-A2 in C2 and format C2 as a percentage to show a 5 percentage-point difference. Label the result clearly so readers do not mistake percentage points for percentage change.

Common Mistakes

Reversing the part and whole: Part divided by whole is the usual direction. A value larger than 100% can be correct, for example when actual sales exceed a target, but check the cell references if the result is unexpected.

Multiplying by 100 and formatting as a percentage: Excel’s percentage format already displays a decimal as a percent. Use a division formula such as =A2/B2, then apply Percent Style; do not add an unnecessary multiplication by 100.

Entering 15 when you mean 15%: If you enter 15 as a regular number and multiply by it, Excel treats it as 15, not 0.15. Enter 15% or 0.15 for a fifteen-percent rate. If the cell shows 1500%, its stored value may be 15; re-enter the rate as 15%.

Using the wrong denominator for change: Percentage change is measured against the original value. Dividing by the new value, or by the difference, does not give the standard increase or decrease.

Confusing blanks, zeros, and missing data: A zero total makes a part-to-whole formula impossible, while an empty cell may be treated differently depending on the formula. Decide whether an empty cell means zero, not yet entered, or not applicable before interpreting the result.

Tips

Give the columns descriptive labels such as Part, Total, and Percent of total. Labels help prevent numerator and denominator mix-ups.
Use consistent number formats. Percentages should appear as percentages, while prices and currency amounts should use an appropriate currency format.
Choose decimal places based on the task. A dashboard may need whole percentages, while a detailed analysis may need one or two decimal places.
When comparing several categories, calculate each category against the same total. If categories are mutually exclusive and cover the full total, their percentages should add to about 100%, allowing for rounding.
Keep source values and calculated percentages in separate columns. This makes it easier to check the calculation and update the source data without overwriting it.

Troubleshooting

The result looks like 0.25 instead of 25%: The calculation may be correct but the cell is formatted as General or Number. Select it and choose Home > Number > Percent Style. If you need a particular number of decimal places, use the decimal-place controls in the Number group.

The result is 2,500% instead of 25%: Check whether the formula multiplies by 100 while the cell is also percentage-formatted. Remove the extra multiplication and use the part divided by whole formula, then apply Percent Style. Also check that the input rate is not 25 instead of 25%.

You see #DIV/0!: The denominator is zero or refers to an empty cell being used as zero. Confirm that the total or original value was entered in the expected cell and is not actually zero. If zero is a valid possibility, you can leave the result blank with an error-handling formula. With the part in A2 and the whole in B2, enter =IFERROR(A2/B2,"") in C2. This displays a blank for any error, so use it only if hiding errors is appropriate; it can also conceal problems other than a zero denominator.

The copied formulas all show the same result: Inspect the references. A fully fixed reference such as $B$2 will not move when copied. Use a relative reference for the changing part and an absolute reference for a shared total, such as =B2/$B$10. If a number is stored as text, convert it to a number before relying on the calculation; a green triangle or left alignment can be a clue, but neither is a definitive test.

Excel shows the formula instead of a result: The cell may be formatted as Text, or Show Formulas may be turned on. Change the cell format to General, re-enter the formula, and check Formulas > Show Formulas. Make sure the entry begins with an equals sign and has no apostrophe before it.

Frequently Asked Questions

What is the basic formula for percentage in Excel?
Divide the part by the whole, then format the result as a percentage. For example, 25 out of 200 is 12.5%.

Do I need to multiply the answer by 100?
No, not when you apply Percentage format. Excel displays the decimal result as a percentage automatically. Multiplying by 100 as well usually makes the displayed result one hundred times too large.

How do I calculate what percentage one number is of another?
Put the first number, the part, in one cell and the comparison total, the whole, in another. Divide the part by the whole and format the answer as a percentage.

How do I calculate a percentage change in Excel?
Subtract the original value from the new value, divide by the original value, and format the result as a percentage. A positive result indicates an increase; a negative result indicates a decrease.

Can a percentage be greater than 100%?
Yes. For example, actual output of 120 against a target of 100 is 120% of target. Check that the part and whole are in the intended order, but do not assume a result above 100% is automatically an error.

Does the formula work in Excel for Mac or Excel for the web?
Yes. The formulas and percentage calculations are the same. The ribbon controls may appear in a different layout, so look for the Percentage format in the Number options. In Excel for the web, changes are generally saved to the workbook automatically.

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More in Formulas & functions

Sources: Function behaviour and menu paths: Microsoft Support documentation for Excel. Method & sources

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