The Percent Change Formula in Excel

To calculate percent change in Excel, use this formula: =((New Value – Old Value) / Old Value) * 100. The result tells you what percentage the value increased or decreased. If the result is positive, the value went up. If it is negative, the value went down.

You do not need to multiply by 100 if you format the cell as a percentage instead — Excel will do that automatically. The simpler version is =((New Value – Old Value) / Old Value), then format as percentage.

The order matters. You always subtract the old value from the new value, then divide by the old value. Reversing this gives you the wrong answer. The old value is your baseline — what you are measuring change from.

Key Takeaways

  • The percent change formula is ((New Value – Old Value) / Old Value) * 100, or leave off the * 100 and format the cell as percentage.
  • Put your old value in one cell and your new value in another, then reference both cells in the formula so you can copy it down for multiple rows.
  • Negative results mean the value decreased; positive results mean it increased.
  • If your old value is zero, Excel returns an error because you cannot divide by zero — this is a real data problem, not a formula mistake.
  • Copy the formula across or down to calculate percent change for many rows at once by clicking the fill handle and dragging.

Setting Up Your Data

Start by putting your old values in one column and your new values in another. For example, put January sales in column B and February sales in column C. Leave column D empty for the percent change calculation.

Click on the first empty cell in column D (next to your first pair of values). Type the formula, but use cell references instead of numbers: =((C2-B2)/B2)*100. Replace C2 and B2 with whatever cells hold your new and old values.

Press Enter. Excel calculates the result and shows it in the cell. If you see a decimal like 0.25, that means 25 percent — you can format it as percentage to see it that way instead.

Copying the Formula Down for Multiple Rows

Once your formula works for the first row, you can copy it to all the other rows at once. Click on the cell with your formula. You will see a small square in the bottom right corner of the cell — this is the fill handle.

Click and drag the fill handle down to the last row of data. Excel copies the formula and adjusts the cell references automatically. Each row now shows the percent change for that pair of values.

If you have many rows, you can also double-click the fill handle instead of dragging. Excel will copy the formula down as far as your data extends in the column to the left.

Formatting as Percentage Instead of Decimal

If your formula does not include * 100, the result appears as a decimal: 0.15 instead of 15%. Both are correct, but percentage format is easier to read. Select the cells with your results, then right-click and choose Format Cells.

In the Format Cells dialog, click the Number tab. Select Percentage from the category list on the left. Choose how many decimal places you want to see — usually zero or one is enough. Click OK.

Your numbers now display as percentages. If you used * 100 in your formula, do not format as percentage — that will multiply by 100 again and give you the wrong number.

Handling Zero and Negative Old Values

If your old value is zero, Excel shows #DIV/0! error. This is not a formula mistake — it is a real problem. You cannot divide by zero mathematically. Check your data to make sure the old value is actually there and not a blank cell or a typo.

If the old value is genuinely zero (like starting inventory was zero), percent change does not have a meaningful answer. You might instead note that the value went from 0 to whatever the new value is, rather than calculating a percentage.

Negative old values work mathematically but can be confusing to interpret. If you started with -10 and ended with 10, the percent change is 200 percent, which is technically correct but unusual in real-world data. Check whether your negative values are real or a data entry error.

Common Mistakes to Avoid

The most common error is reversing the order: subtracting the new value from the old value instead of the other way around. This flips the sign of your answer. Always subtract the old from the new.

Another mistake is forgetting to divide by the old value. If you calculate (New – Old) without dividing, you get the absolute change, not the percent change. These are different things: a change of 10 is not the same as a 10 percent change.

Do not multiply by 100 and then format as percentage. That gives you 2500 percent instead of 25 percent. Pick one method: either multiply by 100 in the formula, or format the cell as percentage, but not both.

Calculating Percent Change for Negative Results

When the percent change is negative, it means the value decreased. A result of -20 means a 20 percent drop. The formula works the same way — you do not need to change anything.

Negative results are common when comparing sales month to month, inventory levels, or any metric that can go down. The formula handles this automatically. If your new value is smaller than your old value, the result will be negative.

Some people add a minus sign or use different formatting for negative numbers to make them stand out. You can do this through Format Cells by choosing a number format that displays negatives in red or with parentheses.

Frequently Asked Questions

What is the difference between percent change and absolute change?

Absolute change is just the difference: new minus old. Percent change shows that difference as a percentage of the old value. A price that goes from $100 to $110 has an absolute change of $10 and a percent change of 10 percent. Percent change lets you compare changes across different starting values.

Can I use this formula for negative numbers?

Yes. If both your old and new values are negative, the formula works normally. If one is negative and one is positive, the result will be a large percent change, which is mathematically correct but can be hard to interpret in real situations.

What does a percent change of 0 mean?

It means the old value and new value are the same — there was no change. The formula will return 0 or 0.00 depending on your formatting.

How do I show percent change with a plus sign for increases?

Format the cells as percentage, then right-click and choose Format Cells. On the Number tab, find a percentage format that shows a plus sign for positive numbers. Some built-in formats include this; if not, you can create a custom format.

Can I calculate percent change between more than two values?

The basic formula compares two values. To track change over three or more time periods, calculate percent change between each pair separately — January to February, then February to March. This shows you the trend step by step.