To calculate a percentage in Excel, divide the part by the whole and format the result as a percentage. For example, type =42/50 in a cell, press Enter, then click Percent Style (%) on the Home tab. Excel shows 84%. With cell references, the formula looks like =B2/C2.
Do not multiply by 100. Excel stores 84% as 0.84, and the percent format handles the display. The rest of this guide covers percent of a total, percent change, adding or removing a percentage, working back to an original number, and fixing results that look wrong.
In This Guide
- Which percentage formula do you need?
- Excel versions these steps cover
- Find a percentage of a total
- Find each row’s share of a grand total
- Calculate percentage change
- Find a percentage of a number
- Increase or decrease a number by a percentage
- Find the original total from a percentage
- Format, check and undo percentages
- Troubleshooting
- Frequently asked questions
Which Percentage Formula Do You Need?
Excel has no single percentage formula. Pick the one that matches your question. In every case, type the formula in an empty cell and press Enter.
| What you want to know | Formula | Example |
|---|---|---|
| What percent is the part of the whole? | =part/whole | =42/50 gives 84% |
| What share of a grand total is each row? | =B2/$B$6 | 1,200 of 3,000 is 40% |
| By what percent did a number change? | =(new-old)/old | 2,342 to 2,500 is 6.75% |
| What is a percent of a number? | =number*percent | 8.9% of 800 is 71.20 |
| Add a percent to a number | =number*(1+percent) | 113 plus 25% is 141.25 |
| Take a percent off a number | =number*(1-percent) | 113 minus 25% is 84.75 |
| What was the number before a discount? | =price/(1-percent) | 15 after 25% off was 20 |
Excel Versions These Steps Cover
The formulas work the same way in Excel for Microsoft 365, Excel 2024, Excel 2021, and the older 2019 and 2016 versions, on Windows and Mac. They also work in Excel for the web. Only a few keys and buttons differ:
- Windows: press Enter to finish a formula. Ctrl + Shift + % applies the percent format.
- Mac: press Return. Control + Shift + % applies the percent format.
- Excel for the web: Microsoft lists Ctrl + Shift + 5 for the percentage format, which is the same key as % on a US keyboard.
You only need a worksheet you can edit. If the file opens in read-only or view mode, turn on editing first.
How to Find a Percentage of a Total
Use this when you have a part and a whole, such as 42 correct answers out of 50 questions.
- Click an empty cell.
- Type an equals sign, the part, a slash and the whole, such as =B2/C2. The part always goes first.
- Press Enter. You’ll see a decimal, like 0.84.
- Select the cell again. On the Home tab, in the Number group, click Percent Style (%). The cell now shows 84%.
- To fill the rest of the column, double-click the small square in the bottom-right corner of the cell. This square is called the fill handle. Excel copies the formula down and adjusts the row numbers for you.
Use Increase Decimal or Decrease Decimal in the same Number group to show more or fewer decimal places. Percent Style on its own shows whole numbers, so 0.875 appears as 88% until you add a decimal place.
Sometimes every row is part of one total at the bottom of the list. Say B2 to B5 hold sales of 1,200, 900, 600 and 300, and B6 holds the total, =SUM(B2:B5), which is 3,000.
- Click C2 and type =B2/$B$6.
- Press Enter, then click Percent Style. C2 shows 40%.
- Copy the formula down to C5. The rows show 40%, 30%, 20% and 10%.
The dollar signs make B6 an absolute reference, which means it stays put when you copy the formula. Without them, the next row would divide by B7, which is empty, and Excel would show an error. To add the dollar signs quickly, click the reference in the formula bar and press F4. On a Mac, press Command + T or F4. Microsoft covers this in Switch between relative, absolute, and mixed references.
A quick check: the shares should add up to 100%. If you want to show them visually, see how to make a pie chart in Excel.
In Excel for Microsoft 365 you can also use the newer PERCENTOF function. =PERCENTOF(B2,B2:B5) returns the same 40%. Microsoft’s PERCENTOF page lists it for Microsoft 365 only, so stick with division if you share the file with people on Excel 2021 or 2024.
How to Calculate Percentage Change
Subtract the old number from the new number, then divide by the old number: =(new-old)/old. Keep the parentheses. Without them, Excel divides before it subtracts and gives the wrong answer.
- Earnings went from $2,342 to $2,500: =(2500-2342)/2342 gives 6.75%, an increase.
- Earnings went from $2,500 to $2,425: =(2425-2500)/2500 gives -3.00%, a decrease.
With cell references, put the old value in B2 and the new value in C2, then type =(C2-B2)/B2 in D2. Apply Percent Style and click Increase Decimal twice to see two decimal places. A positive result is an increase. A negative result is a decrease.
If your numbers run down one column, such as monthly sales in B2 to B13, start in the second row. Type =(B3-B2)/B2 in C3 and copy it down. Each row is then compared with the row above it. To compare every month with the first month instead, lock the first cell: =(B3-$B$2)/$B$2.
How to Find a Percentage of a Number
Multiply the number by the percentage. To find 8.9% sales tax on $800, type =800*0.089 (or =800*8.9%). The answer is $71.20.
With cell references, put the price in B2 and the rate in C2, then type =B2*C2. Enter the rate as 8.9% or 0.089, not as 8.9. A plain 8.9 makes Excel multiply by 8.9, and the tax comes out as 7,120.
How to Increase or Decrease a Number by a Percentage
Multiply by 1 plus the percentage to add it, or 1 minus the percentage to take it off. In these formulas, 1 stands for 100%.
- Increase: =113*(1+0.25) gives 141.25, which is $113 plus 25%.
- Decrease: =113*(1-0.25) gives 84.75, which is $113 minus 25%.
- With cells: amount in B2 and percentage in C2, type =B2*(1+C2) or =B2*(1-C2).
A common slip is typing =100+10% and expecting 110. Excel reads 10% as 0.1, so the answer is 100.1. Use =100*(1+10%) instead.
Change a Whole Column Without a Formula
Warning: this method overwrites your original numbers. Copy the column to a spare column first, or be ready to press Ctrl + Z (Command + Z on a Mac) right away if the result looks wrong.
These are the steps Microsoft gives for Excel on Windows in Multiply by a percentage in Excel:
- In an empty cell, type the multiplier. Use =1+15% to add 15%, =1-15% to subtract 15%, or just 15% to get 15% of each number.
- Select that cell and press Ctrl + C.
- Select the numbers you want to change.
- Right-click the selection and click Paste Special. Click the words, not the arrow next to them.
- Select Values, then Multiply, then click OK. Every selected number is replaced with the new amount.
How to Find the Original Total From a Percentage
If a shirt costs $15 after 25% off, it is 75% of the original price. Type =15/0.75 to get the original price, $20. With cells, put the sale price in B2 and the discount in C2, then type =B2/(1-C2).
Do not add the discount back with =15*(1+0.25). That gives $18.75, because 25% of the smaller sale price is less than 25% of the original price.
The same idea removes a percentage that was added. If $108 includes 8% tax, =108/(1+8%) returns the pre-tax price, $100.
How to Format, Check and Undo Percentages
Formatting only changes how a number looks. The cell still holds the decimal, which you can confirm by clicking the cell and reading the formula bar. Microsoft explains the rules in Format numbers as percentages in Excel.
Set the Decimal Places in Format Cells
- Select the cells with your percentages.
- Press Ctrl + 1 (Command + 1 on a Mac) to open Format Cells. On Windows you can also click the small arrow in the corner of the Number group. On a Mac, open the number format list on the Home tab and choose More Number Formats.
- In the Category list, select Percentage.
- Type a number in the Decimal places box, such as 0 for 10% or 2 for 10.00%, and click OK.
If trailing zeros keep disappearing in other number cells, see how to keep the second decimal place in Excel.
Know What Happens When You Type Into Percent Cells
- Cells that already hold numbers: applying the percent format multiplies what you see by 100. A cell that contains 10 turns into 1000%.
- Empty cells formatted first: Microsoft says typing 10 or 0.1 both give 10%. Numbers of 1 or more are treated as the percent you typed.
Make Negative Percentages Stand Out
Open Format Cells, choose the Custom category, and type 0.00%;[Red]-0.00% in the Type box. Decreases then appear in red. You can get a similar result with a rule that colors cells below zero; our guide to coloring cells with IF formulas in Excel shows how those rules work.
Undo the Percent Format
Press Ctrl + Z straight after the change. Later on, select the cells, open Format Cells and choose General. The percent sign goes away and the decimal comes back, so 84% shows as 0.84.
Troubleshooting Percentage Formulas
| What you see | Why | Fix |
|---|---|---|
| 0.84 instead of 84% | The cell uses the General or Number format. | Select it and click Percent Style. |
| 8400% instead of 84% | The formula multiplies by 100 and the cell also has the percent format. | Remove *100 from the formula. |
| 119% instead of 84% | The whole is on top and the part is on the bottom. | Swap them so the part comes first. |
| #DIV/0! | The formula divides by zero or by an empty cell. | Fill in the divisor, lock the total with dollar signs, or use the IF formula below. |
| An answer 100 times too big | A rate was typed as 15 instead of 15%. | Retype the rate as 15% or 0.15. |
| #VALUE! or shares that do not reach 100% | Some numbers are stored as text. | Convert them to real numbers, then check the total again. |
| The formula itself shows in the cell | The cell was formatted as Text before you typed. | Change the format to General, then press F2 and Enter in the cell. |
| The percent buttons are grayed out | The sheet is protected or the file is read-only. | Turn on editing, or ask the owner to unprotect the sheet. |
Hide #DIV/0! Until the Numbers Are In
A percentage change from zero has no answer, and a blank total gives the same error. Microsoft’s How to correct a #DIV/0! error page suggests testing the divisor with IF. For a percentage change, type =IF(B2,(C2-B2)/B2,””). The cell stays blank while B2 is empty or zero.
=IFERROR((C2-B2)/B2,””) also works. Microsoft warns that IFERROR hides every kind of error, not just this one, so check that the plain formula is right before you wrap it.
If a result does not change after you edit a number, calculation may be set to Manual. See how to make an Excel spreadsheet update automatically.
Frequently Asked Questions
Is there a percentage function in Excel?
There is no function called PERCENTAGE. A percentage is a division, so =part/whole with the percent format does the job in every version. Excel for Microsoft 365 adds PERCENTOF, which divides the sum of a subset by the sum of the full range.
Do I need to multiply by 100?
No, as long as you use the percent format. The format shows 0.84 as 84%. Only multiply by 100 if you want a plain number such as 84 in a cell that keeps the General format.
How do I calculate 20% of a number in Excel?
Multiply the number by 20%. If the number is in A2, type =A2*20% or =A2*0.2. For 250, both return 50.
What is the shortcut for the percent format?
On Windows, select the cells and press Ctrl + Shift + %. On a Mac, press Control + Shift + %. Microsoft’s shortcut list says this applies the percentage format with no decimal places.
Why don’t my percentages add up to 100%?
It is usually rounding on screen. Three shares of 33.33% each display as 33% and appear to total 99%, while the stored values still total 100%. Click Increase Decimal to see more digits. If the stored total is also off, look for numbers saved as text or a formula that divides by the wrong total.
What is the difference between percent and percentage points?
Percentage points are a simple subtraction of two percentages. A rate that goes from 20% to 25% rises by 5 percentage points. Measured with the percentage change formula, =(25%-20%)/20%, the same move is a 25% increase.
Do these formulas work in Excel for the web and on a Mac?
Yes. The formulas are identical. On a Mac you press Return instead of Enter, and the percent shortcut uses the Control key. In Excel for the web, the percent format is on the Home tab as well.
Next Step
Start with =part/whole and Percent Style, then use the table near the top of this page when the question changes. The worked examples here match Microsoft’s Calculate percentages article, which is a good page to bookmark.
More Excel Guides
- How to AutoFit columns and rows in Excel
- How to fill a cell with color in Excel
- How to keep the second decimal place in Excel
For a finance example that uses percentages, see how to calculate CAPM in Excel.
Matthew Burleigh has been writing tech tutorials since 2008. His writing has appeared on dozens of different websites and been read hundreds of millions of times.
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