Percent change formula in Excel, with a worked example

The percent change formula

Percent change = (new value − old value) ÷ old value

You always divide by the old value, the base you compare against. In Excel, with last year in column B and this year in column C, type =(C2-B2)/B2 in the first row, copy it down and click the % button (or press Ctrl+Shift+%). The brackets matter: without them Excel divides first and subtracts afterwards.

=C2/B2-1 gives exactly the same result and is a little shorter. Tents: 96,600 ÷ 84,000 − 1 = 0.15, shown as 15.0%. Excel stores 0.15, the % format only changes how it is displayed.

Worked example: percent change for an outdoor shop

Yellow cells are inputs. Column D is the dollar change and column E the percent change. Rows 10 and 11 compare the ABS fix with the plain formula for a loss that turned into a profit, and rows 14 to 20 answer the related questions from this guide.

Worked example: percent change for an outdoor shop

	A	B	C	D	E
1	Product line	2025 ($)	2026 ($)	Change ($)	% change
2	Tents	84,000	96,600	12,600	15.0%
3	Backpacks	52,500	49,350	-3,150	-6.0%
4	Footwear	61,200	67,932	6,732	11.0%
5	Climbing gear (new)	0	18,400	18,400	new
6	Accessories	23,800	25,466	1,666	7.0%
7	Total	221,500	257,748	36,248	16.4%
8
9	Loss to profit	2025 ($)	2026 ($)	Change ($)	% change
10	Net profit, ABS base	-8,000	4,000	12,000	150.0%
11	Net profit, plain formula	-8,000	4,000	12,000	-150.0%
12
13	Related questions	Value
14	Conversion rate 2025	2.4%
15	Conversion rate 2026	3.0%
16	Change in percentage points	0.6
17	Percent change of the rate	25.0%
18	Tents 2027 at +10%	106,260
19	Back from 2026 to 2025	84,000
20	Biggest decline	-6.0%

Fictional shop, illustrative figures. The formulas work the same way in Google Sheets.

Percent increase and percent decrease

There is no separate formula for a decrease. The same formula returns a negative number when the value fell: backpacks went from $52,500 to $49,350, a change of −$3,150 or −6.0%. Footwear grew 11.0% and accessories 7.0%. To find the biggest decline in a column, use =MIN(E2:E6), which returns −6.0% here.

For the total, calculate the change from the totals, not from the percentages above it: $221,500 to $257,748 is 16.4%. An average of the line percentages would give every product line the same weight, however small it is.

If you want a plus sign on increases, use a custom number format such as +0.0%;-0.0%;0.0% (Format Cells › Custom). It changes only the display, not the value.

When the old value is zero: #DIV/0!

The shop started selling climbing gear in 2026, so the 2025 value is 0. Growth from nothing is not defined, and =(C5-B5)/B5 returns #DIV/0!. Show a label instead: =IFERROR((C5-B5)/B5,"new"). The stricter version, =IF(B5=0,"new",C5/B5-1), only catches the zero and still shows any other error, which is safer in a model.

A text label has a second advantage: MIN, MAX and AVERAGE skip text, but a single #DIV/0! in the range turns their result into an error too. The dollar change still works, so report the $18,400 for a new line.

Percent change with negative numbers

Net profit went from a loss of $8,000 to a profit of $4,000. That is an improvement of $12,000, but the plain formula returns −150.0%, because it divides by a negative number. Divide by the absolute value of the base instead: =(C10-B10)/ABS(B10) gives +150.0%, and the sign now matches the direction of the change.

Even with ABS, a percentage change from a negative base is hard to read. Many financial reports print "n.m." (not meaningful) when either year is a loss and show the dollar change instead. Whichever rule you use, apply it to the whole report.

Percentage points vs percent change

When the values are already percentages, there are two different answers. The online shop's conversion rate rose from 2.4% to 3.0%. That is 0.6 percentage points (=B15-B14, which the example multiplies by 100 to show the points), but a 25.0% percent change (=B15/B14-1), because 3.0 is a quarter more than 2.4. Say which one you mean. "Conversion rose 0.6%" is ambiguous, "rose 0.6 points" or "rose 25%" is not.

Working forwards and backwards

To increase a value by a percentage, multiply by 1 plus the rate: tents at +10% next year are =C2*(1+10%) = $106,260. To decrease, use 1 minus the rate.

To find the original value from the new value and the percent change, divide instead: =C2/(1+E2) = 96,600 ÷ 1.15 = $84,000. A common slip is to take 15% off the new value: 96,600 × (1 − 15%) = $82,110, which is wrong because the 15% was measured on the old base.

For growth over several years, a single percent change hides the path. The CAGR formula turns it into one yearly rate. And if the percentage is profit on a price, check whether it is a markup or a margin: the markup vs margin guide shows why they differ.

Common mistakes

• Dividing by the new value. =(C2-B2)/C2 answers a different question and returns 13.0% instead of 15.0% for the tents. The base is always the old value.
• Leaving out the brackets. =C2-B2/B2 calculates 96,600 − 1. Put the subtraction in brackets, or use =C2/B2-1.
• Multiplying by 100 and then formatting as %. The % format already multiplies by 100 for display, so the 15% becomes 1,500%. Do one or the other.
• Averaging percentages for a total. Calculate the total change from the total values, so that large lines count more than small ones.
• Dividing by a negative base. The sign flips and an improvement looks like a decline. Use ABS in the denominator or report "n.m.".
• Calling a difference of two rates a percent. From 2.4% to 3.0% is 0.6 percentage points, or a 25% increase, never "0.6%".