The Basic Formula for Percentage Change

To calculate percentage change in Excel, subtract the original value from the new value, divide by the original value, and multiply by 100. The formula is: ((New Value – Original Value) / Original Value) × 100.

In Excel syntax, if your original value is in cell A1 and your new value is in cell B1, you would write: =((B1-A1)/A1)*100. This gives you the percentage change as a positive or negative number. A positive result means an increase; a negative result means a decrease.

You can also format the result as a percentage by removing the ×100 from the formula—=((B1-A1)/A1)—and then explore percentage formatting to the cell. Right-click the cell, select Format Cells, choose Percentage, and set your decimal places. Excel will automatically multiply by 100 and add the % symbol.

Key Takeaways

  • The percentage change formula is ((New Value – Original Value) / Original Value) × 100, entered in Excel as =((B1-A1)/A1)*100.
  • You can skip the ×100 in the formula and instead format the cell as a percentage to display the result with a % symbol.
  • Copying the formula down a column lets you calculate percentage change for multiple rows at once using relative cell references.
  • Wrapping the formula in ABS() removes the negative sign if you only want to see the magnitude of change, useful for comparing increases and decreases side by side.
  • A #DIV/0! error means your original value is zero, which makes the calculation impossible.

Setting Up Your Data in Columns

Arrange your data so the original values are in one column and the new values are in another. For example, put original values in column A starting at A2, and new values in column B starting at B2. Leave row 1 for headers like "Original" and "New".

Click on cell C2 to enter your percentage change formula there. Type =((B2-A2)/A2)*100 and press Enter. The result appears in C2. If you want to see the result as a percentage instead of a decimal multiplied by 100, use =((B2-A2)/A2) and format the column as percentage.

Once your formula is in C2, click the cell and drag the small square at the bottom-right corner down to copy the formula to the rows below. Excel automatically adjusts the cell references (A2 becomes A3, B2 becomes B3, and so on), so each row calculates its own percentage change.

Formatting Results as Percentages

If you use the formula without ×100—=((B2-A2)/A2)—the result displays as a decimal like 0.25 instead of 25%. To show it as a percentage, select the cells containing your results, right-click, and choose Format Cells.

In the Format Cells dialog, click the Number tab, select Percentage from the category list on the left, and set the number of decimal places you want (usually 0 or 2). Click OK. Excel multiplies the decimal by 100 and adds the % symbol automatically.

Alternatively, select your result cells and click the % button in the toolbar. This applies percentage formatting when ready, though it may round to zero decimal places by default. You can adjust decimal places using the increase or decrease decimal buttons next to the % button.

Handling Negative Values and Zero

When the original value is negative and the new value is positive (or vice versa), the percentage change formula still works, but the result can be counterintuitive. For example, if you go from –10 to +10, the percentage change is ((10–(–10))/–10)×100 = –200%, which is mathematically correct but may not match what you expected.

If your original value is zero, Excel returns a #DIV/0! error because you cannot divide by zero. To prevent this error, wrap your formula in an IF statement: =IF(A2=0,"N/A",((B2-A2)/A2)*100). This displays "N/A" instead of an error when the original value is zero.

To show only the magnitude of change without the negative sign, use the ABS function: =ABS(((B2-A2)/A2)*100). This is useful when you want to compare the size of increases and decreases side by side without worrying about direction.

Using Percentage Change in Real Scenarios

Percentage change is useful for tracking sales growth, price increases, inventory levels, or any metric that changes over time. If you have monthly sales figures, put January in column A and February in column B, then calculate the percentage change to see how much sales grew or shrank month to month.

You can also use percentage change to compare performance across different products or departments. If Product A grew 15% and Product B grew 8%, the percentage change formula shows you which performed better relative to its starting point, even if their absolute sales numbers are very different.

For multi-period tracking, you can calculate percentage change from the same baseline (like January) for all months, or calculate month-to-month change. The formula stays the same; only which cells you reference changes. Month-to-month means comparing February to January, March to February, and so on. Baseline comparison means comparing every month to January.

Common Mistakes to Avoid

The most common error is reversing the order of subtraction. Remember: subtract the original from the new, not the other way around. If you subtract new from original, you get the opposite sign, which flips the meaning of your result.

Another mistake is forgetting to divide by the original value. The formula =((B2-A2)*100) without the division gives you a meaningless number. The division by the original value is what makes the change relative to where you started, which is what percentage means.

If you copy a formula down and the results look wrong, check whether you used absolute references where you needed them. If you want all rows to compare against the same original value (like a baseline year), use $A$2 instead of A2 so that reference does not change when you copy the formula down.

Frequently Asked Questions

What is the difference between percentage change and percentage point change?

Percentage change is relative to the original value, calculated with the formula ((New – Original) / Original) × 100. Percentage point change is the straightforward difference between two percentages. If unemployment was 5% and is now 7%, the percentage point change is 2 points, but the percentage change is 40% (because 7 is 40% higher than 5).

Can I calculate percentage change if both values are negative?

Yes. The formula works the same way. If you go from –50 to –30, the percentage change is ((–30–(–50))/–50)×100 = 40%. The negative signs in the calculation matter, so be careful with your parentheses and check your result makes sense in context.

How do I show percentage change with one decimal place?

If you format as percentage, right-click the cell, choose Format Cells, select Percentage, and set decimal places to 1. If you use the ×100 formula, format the cell as a number with 1 decimal place instead. Either way, Excel rounds the display to one decimal place without changing the underlying calculation.

What does a negative percentage change mean?

A negative percentage change means the value decreased. For example, –25% means the new value is 25% lower than the original. The negative sign tells you the direction of change; the number tells you the size of that change relative to where you started.

How do I calculate the average percentage change across multiple periods?

Calculate the percentage change for each period separately using the formula, then use the AVERAGE function on those results. For example, if your percentage changes are in cells C2 through C13, type =AVERAGE(C2:C13) in another cell. This gives you the average of all the individual percentage changes.