#### in Excel Cell: How to Fix and Prevent this Error

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By Matthew Simpson

Have you ever been working in Excel and needed to calculate the percentage of a total? Maybe you’re trying to figure out what portion of your budget went to groceries or how much of a project is complete. Calculating percentages is a common task, and it’s pretty simple once you know the steps. Here’s how to do it.

Step by Step Tutorial: Calculating Percentage in an Excel Cell

Before we dive into the steps, let’s clarify what we’ll achieve by the end of this tutorial. We’re going to learn how to use a formula that will calculate the percentage of a number in relation to another number in Excel.

Step 1: Identify the Numbers

First things first, you need to know which numbers you are working with.
When you’re calculating a percentage, you’ll have a part (the amount you’re trying to find the percentage for) and a whole (the total or 100% value). Make sure you have both of these numbers in your Excel sheet.

Step 2: Input the Percentage Formula

In the cell where you want the percentage to appear, type in the formula: =part/whole.
This is the basic formula for calculating percentage. The part is divided by the whole, and then Excel will do the math to give you the percentage.

Step 3: Format as Percentage

After you’ve input the formula, you’ll want to format the cell to display the number as a percentage.
To do this in Excel, you can either click on the ‘Percentage Style’ button in the ‘Home’ tab or right-click on the cell, select ‘Format Cells’, and then choose ‘Percentage’. This will convert the decimal number that appears after you input the formula into a percentage.

After completing these steps, the cell will display the percentage of the part relative to the whole. For example, if your part is 50 and your whole is 200, the formula will calculate this as 0.25. Formatting the cell as a percentage will then display this as 25%.

Tips for Calculating Percentage in an Excel Cell

  • Make sure your numbers are accurate before you begin. A small error in your part or whole can significantly change the percentage.
  • Remember to always divide the part by the whole, not the other way around.
  • If you want to show the percentage as a decimal, simply skip step 3.
  • Use parentheses in your formula to ensure the correct order of operations. For example, if you’re calculating the percentage of a sum, your formula might look like this: =(A1+A2)/B1.
  • Excel automatically multiplies the result of a percentage formula by 100. There’s no need to include "*100" in your formula.

Frequently Asked Questions

What if I want to calculate a percentage increase or decrease?

To calculate a percentage increase, subtract the original number from the new number, then divide the result by the original number and multiply by 100. For a decrease, it’s the same process, but you start with the new number and subtract the original number.

Can I use this method to calculate a percentage of a percentage?

Yes, you can. Just apply the same formula, but make sure your ‘part’ is also formatted as a percentage.

What if my ‘whole’ is a sum of multiple cells?

If your total is the sum of multiple cells, you can either add them up in the formula itself using the plus symbol (+) or calculate the sum in a separate cell and reference that cell in your formula.

How do I subtract a percentage from a number in Excel?

To subtract a percentage, first calculate the percentage of the number using the steps above, then subtract that result from your original number.

Can I calculate a percentage of a total that includes negative numbers?

Yes, percentages can be calculated with negative numbers, just be careful with your formula and make sure you’re using parentheses where necessary to maintain the correct order of operations.


  1. Identify the numbers you’ll be using (the part and the whole).
  2. Input the formula =part/whole in the desired cell.
  3. Format the cell to display the result as a percentage.


Calculating the percentage in an Excel cell is a fundamental skill that can be applied in many scenarios – from budgeting to data analysis. It’s one of those Excel tricks that can make your work much more efficient and your data more interpretable. The ability to quickly figure out what fraction of the whole something represents is invaluable in decision-making processes and can be used to display data trends over time, assess financial growth, or measure efficiency across various business operations. With the simple formula of dividing the part by the whole and multiplying by 100, you’re well on your way to becoming an Excel pro. Whether you’re a student, a professional, or just someone looking to get a better handle on their personal finances, mastering the percentage calculation in Excel is a must. So why not give it a try yourself?