The basic formula for percent increase

To calculate a percent increase in Excel, subtract the original value from the new value, divide that result by the original value, then multiply by 100. The formula looks like this: =(New Value - Original Value) / Original Value * 100

In practice, if your original value is in cell A1 and your new value is in cell B1, you would type =((B1-A1)/A1)*100 into an empty cell. Excel calculates the result when ready. If the number is negative, the value actually decreased rather than increased.

You can also skip the multiplication by 100 and format the cell as a percentage instead — Excel will display the decimal as a percent automatically. This is often cleaner if you are building a spreadsheet others will read.

Key Takeaways

  • The percent increase formula is (New Value - Original Value) / Original Value * 100, entered as a single line in any empty cell.
  • If you multiply by 100 in the formula, the result displays as a number like 15 (meaning 15 percent); if you omit the *100 and format as percentage, it displays the same way.
  • Negative results mean the value decreased, not increased — a -10 result means a 10 percent decrease.
  • You can copy the formula down a column to calculate percent increase for dozens of rows at once by using relative cell references like A1 and B1.

Setting up your data in columns

Before you write any formula, organize your spreadsheet so the original values are in one column and the new values are in another. For example, put "Original Price" as a header in column A and "New Price" in column B. Put the actual numbers below each header, starting in row 2.

This layout makes the formula easier to write and easier to copy down if you have multiple rows. It also makes the spreadsheet readable for anyone else who opens it later — they can see at a glance what each column represents.

Writing the formula in a new column

Click on an empty cell in column C, row 2 (or wherever your first data row is). Type the formula =((B2-A2)/A2)*100 and press Enter. Excel calculates the percent increase for that row and displays the result.

If you want the result to show as a clean percentage like "15%" instead of "15", you can format the cell differently. Right-click the cell, select "Format Cells", choose "Percentage" from the Category list, and click OK. Excel will display the same number but with a percent sign.

Copying the formula to multiple rows

If you have 50 rows of data, you do not need to type the formula 50 times. Click on the cell where you wrote the formula (C2 in the example above). You will see a small square in the bottom-right corner of the cell — this is the fill handle. Click and drag it down to the last row of your data.

Excel automatically adjusts the cell references as it copies down. Row 3 becomes =((B3-A3)/A3)*100, row 4 becomes =((B4-A4)/A4)*100, and so on. This is called a relative reference, and it saves enormous amounts of time.

Alternatively, you can click the cell with the formula, copy it (Ctrl+C or Cmd+C), then select the range where you want to paste it and paste (Ctrl+V or Cmd+V).

Handling zero and negative original values

If your original value is zero, the formula will return an error because you cannot divide by zero. Excel displays #DIV/0! in the cell. This is correct behavior — percent increase from zero is mathematically undefined, not a number you can calculate.

If your original value is negative and your new value is positive (or less negative), the formula still works, but the interpretation is tricky. A change from -10 to 10 is technically a 200 percent increase, but that number often confuses people. Consider whether percent change makes sense for your data, or whether absolute change (just subtracting the two numbers) would be clearer.

Common mistakes and how to fix them

The most common error is forgetting the parentheses around (B1-A1). If you type =B1-A1/A1*100, Excel follows the order of operations and divides A1 by A1 first, giving you the wrong answer. Always put the subtraction in parentheses: =((B1-A1)/A1)*100.

Another mistake is mixing up which value is original and which is new. If you reverse them, a price increase becomes a decrease. Check your headers and your logic: if the new value should be larger, the result should be positive.

If your result looks wildly wrong — like 5000 instead of 50 — you probably multiplied by 100 in the formula and then formatted the cell as a percentage, which multiplies by 100 again. Remove the *100 from the formula or remove the percentage formatting, but not both.

When to use percent increase vs. absolute change

Percent increase tells you the relative change — how much something grew compared to where it started. A $10 increase on a $100 item is 10 percent; a $10 increase on a $1,000 item is 1 percent. Percent increase makes the comparison fair.

Absolute change is just the difference: $1,000 minus $900 is $100. Use absolute change when you care about the actual dollar amount or unit, not the rate of growth. Many spreadsheets include both columns so readers can see both perspectives.

Frequently Asked Questions

What if I want to show the result as a decimal instead of a percentage?

Remove the *100 from the formula: =((B1-A1)/A1). The result will be a decimal like 0.15 (meaning 15 percent). You can then format it as a percentage by right-clicking, selecting Format Cells, and choosing Percentage, or leave it as a decimal if that is clearer for your audience.

Can I calculate percent increase if the original value is negative?

The formula works mathematically, but the result is often confusing. A change from -50 to -30 is technically a 40 percent increase, but most people find that counterintuitive. Consider whether absolute change (the difference between the two numbers) or a different metric would be more useful for your analysis.

How do I show a percent decrease instead?

Use the same formula — it handles both increases and decreases automatically. If the new value is smaller than the original, the result will be negative, like -15, meaning a 15 percent decrease. Some people prefer to write it as "decreased by 15 percent" rather than "increased by -15 percent."

What does #DIV/0! mean in my cell?

It means you are dividing by zero, which happens when your original value is zero. Percent increase from zero is undefined mathematically. You can either leave the cell blank, type "N/A", or use an IF statement to check for zero first: =IF(A1=0,"N/A",((B1-A1)/A1)*100).