Calculating Percentage Change in Excel

What this does

Percentage change tells you how much a value rose or fell relative to where it started, which is what makes a €20 move on €100 (20%) and a €20 move on €400 (5%) comparable. Subtracting old from new gives the absolute change; dividing by the old value rebases it to a rate. A positive result is an increase, a negative one a decrease. The same idea underpins a lot of everyday Excel work, so the few minutes spent getting it right here pay back across every sheet you build afterwards. Treat it as a pattern, not a one-off, and it stops being something you look up and starts being something you reach for. The difference between a quick fix and a sheet you can trust is the extra minute you spend validating “calculating percentage change in excel”. Start on a copy or a tiny sample, keep the affected cells visible, and compare the result with the tool above before you touch the real workbook. When a formula is involved, keep the inputs labelled beside it, reference cells instead of typing values, and apply number formatting only after the result checks out. The point is a calculation you can defend to a CFO or an auditor, but the practical win is that someone else can open the file and understand what happened without asking you.

A worked example

A price goes from 120 to 168: =(168-120)/120 = 0.4, formatted as 40% — a 40% increase. If it instead fell to 90, =(90-120)/120 = −25%. The tool above colours increases green and decreases red and also shows the raw unit change, so you see both the rate and the absolute move. Percentage change is the language of every trend: month-on-month revenue, year-on-year growth, price moves, conversion shifts. It turns two raw numbers into a comparable story anyone can read at a glance. A practical tip before you scale it up: build it once on a small block of test data, confirm the number against the tool on this page, and only then point it at your real sheet. That one habit catches almost every mistake while it is still cheap to fix, long before a wrong figure reaches a report or a colleague.

In Google Sheets

Google Sheets handles this almost identically to Excel. The formula syntax above is the same, and the menu lives under a slightly different label rather than a ribbon tab. Use the platform toggle at the top of the page to switch every keyboard shortcut between Windows and Mac, and expect at most cosmetic differences in naming. Nothing on this page is behind a login: the tool runs entirely in your browser, the formula is shown in full with one-click copy, and the steps work the same on Windows and Mac. That is the whole promise here — the exact answer, a way to prove it on your own numbers, and just enough context to make it stick. Here is the takeaway for “calculating percentage change in excel”: copy the answer if you are busy, but if you have a spare few minutes, rebuild the example in Excel yourself with the tool above open beside it. That single pass — type it, run it, watch the result move when you change an input — is what turns a formula you found into a technique you trust. Keep your inputs labelled and referenced, never hard-coded, and the same sheet stays correct and auditable as it grows. Done that way, you will not need to look this up again, and you will be the person others ask.

Common mistakes

• Dividing by the new value instead of the old — the base must be the starting point.
• Leaving the result as a decimal (0.4) instead of formatting it as 40%.
• Averaging percentage changes across periods instead of compounding them.
• Dividing by zero when the original value is 0, which has no defined percentage change.

Frequently asked questions