How Do You Calculate Percentage Increase OR Decrease 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. For “calculate percentage increase or decrease in excel”, the reliable version is a short checking loop, not just the first command that appears to work. Run it on a deliberately small range first, watch how the affected cells change, and only then apply the same setup to the full sheet. 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. That is what makes a calculation you can defend to a CFO or an auditor useful in real work: repeatable, auditable, and not dependent on memory or luck.

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. If there is any chance you will reuse this, drop it into a small template tab right now: a labelled input area on the left and the formula beside it, checked once against the tool above. Next time the same question comes up, the answer is a single paste away instead of a rebuild from memory.

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. The short version of “calculate percentage increase or decrease in excel”: the answer is at the top of this page, the tool proves it on your own numbers, and the sections above explain why it holds so the next variation does not stump you. Excel rewards people who reference cells instead of typing values and who keep inputs separate from formulas, because that is what makes a result you can audit months later. Build it once, deliberately, with the live tool as a check, and you convert a one-off lookup into a reusable skill — which is the whole point of learning the why and not just the what.

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