The basic formula for percentage change

To find percentage change in Excel, use this formula: =(New Value – Old Value) / Old Value. Then format the result as a percentage. Excel will multiply by 100 and add the % symbol automatically.

For example, if a cell contains your old value (say, B2) and another contains your new value (C2), you would type =((C2-B2)/B2) in a new cell. If the old value was 50 and the new value is 75, the result shows 0.5, which formats to 50%.

The formula works the same way whether your values went up or down. A decrease shows as a negative percentage. If you started with 100 and ended with 60, the result is –0.4, or –40%.

Key Takeaways

  • The percentage change formula is (New Value – Old Value) / Old Value, entered as =((C2-B2)/B2) if your values are in columns B and C.
  • After entering the formula, right-click the cell, select Format Cells, choose Percentage, and click OK to display the result as a percentage instead of a decimal.
  • You can copy the formula down to calculate percentage change for multiple rows at once by clicking the cell and dragging the fill handle (small square at the bottom right) down.
  • Negative results mean the value decreased; positive results mean it increased.
  • If your old value is zero, Excel shows a #DIV/0! error because you cannot divide by zero — this is a data problem, not a formula problem.

Formatting the result as a percentage

Excel shows the raw calculation as a decimal (0.5 for 50%). To display it as a percentage, select the cell with your formula, right-click, and choose Format Cells. In the window that opens, click the Number tab, select Percentage from the list on the left, and click OK.

You can also use the percentage button in the toolbar. Select your cell and click the % button in the Home ribbon. This applies the percentage format instantly. If you want to control how many decimal places show (for example, 50.25% instead of 50%), right-click and choose Format Cells again, then adjust the decimal places field.

Copying the formula to multiple rows

If you have a list of old and new values and need to calculate percentage change for each pair, enter the formula once, then copy it down. Click the cell containing your formula, then look for the small square at the bottom right corner of the cell — this is the fill handle.

Click and drag that square down to the last row you need. Excel automatically adjusts the cell references for each row. If your formula was =((C2-B2)/B2) in row 2, it becomes =((C3-B3)/B3) in row 3, and so on. This saves you from typing the formula over and over.

Handling common errors

The most common error is #DIV/0!, which means Excel tried to divide by zero. This happens when your old value is zero. You cannot calculate a meaningful percentage change from zero, so check your data. If zero is correct, you may need to note that separately rather than use the percentage change formula.

Another issue is forgetting to format as a percentage. The formula is correct, but the result looks wrong because it shows as a decimal. Simply apply percentage formatting and the display fixes itself — the calculation does not change.

If your result seems backwards (a decrease shows as positive, or vice versa), check which column is old and which is new. The formula subtracts the old value from the new value. If you reversed them, the sign flips.

Percentage change with negative starting values

The formula works differently when your old value is negative. If you started at –50 and moved to 50, the calculation is (50 – (–50)) / (–50) = 100 / (–50) = –2, or –200%. This is mathematically correct but can feel counterintuitive because the value actually increased in real terms.

When working with data that includes negative numbers, double-check your results make sense in context. Some analysts use absolute value (the number without the sign) in the denominator for this reason, but the standard formula above is what most people expect.

Using percentage change in larger spreadsheets

In a real spreadsheet, you might have product names in column A, last month's sales in column B, this month's sales in column C, and percentage change in column D. Set up your formula in D2, format it as a percentage, then copy it down to all rows with data. You can then sort by column D to see which products grew or shrank the most.

You can also use percentage change as part of a larger calculation. For instance, if you want to flag any product that grew more than 20%, use an IF statement: =IF(((C2-B2)/B2)>0.2,"High Growth",""). This shows "High Growth" only when percentage change exceeds 20%.

Frequently Asked Questions

What if I want to show percentage change as a whole number without decimals?

Right-click the cell, select Format Cells, choose Percentage, and set decimal places to 0. A result of 0.5 then displays as 50% instead of 50.00%. You can adjust this number up or down depending on how precise you need the display to be.

Can I calculate percentage change if my values are in rows instead of columns?

Yes. If your old value is in B2 and new value is in C2, the formula is the same. If they are in the same row but different columns, adjust the cell references accordingly. The structure of the formula never changes — only the cell letters and numbers.

Why does my percentage change show as a decimal like 0.5 instead of 50%?

The formula calculates correctly, but the cell is not formatted as a percentage. Select the cell and click the % button in the toolbar, or right-click and choose Format Cells, then Percentage. The number itself does not change — only how Excel displays it.

What does a negative percentage change mean?

A negative result means the value decreased. If you had 100 and now have 60, the percentage change is –40%. The negative sign tells you the direction of change. A positive percentage means the value increased.

Can I use this formula to compare values from different time periods?

Yes. The formula works for any old and new values, whether they are from different months, years, or any other time period. Just make sure your old value is in the denominator and your new value is in the numerator, and the calculation is correct.