Excel Depreciation Function

What this does

Depreciation spreads the cost of an asset across the years it is used, so each period carries a fair share of the expense instead of one big hit at purchase. Straight-line (SLN) charges the same amount every year; declining-balance (DDB) front-loads the expense, matching assets that lose most value early, like vehicles and laptops. 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 “excel depreciation function”. Start on a copy or a tiny sample, keep the affected formula 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 €10,000 machine with a €2,000 salvage value and a 5-year life depreciates by =SLN(10000,2000,5) = €1,600 every year under straight-line. Switch to declining balance and the first-year charge is larger — €4,000 — then tapers. The table and book-value curve above redraw the whole schedule as you change any input. You need a depreciation schedule for any fixed-asset register, a capex budget, or a P&L that has to match expense to the period that benefited. It is core to both management reporting and tax compliance. 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. Keep this page bookmarked for the next time the same question comes up. Better still, rebuild the example once in your own sheet — doing it yourself, with the tool above to check against, is what turns a copied formula into a technique you own. Treat “excel depreciation function” as a small building block rather than a chore. Once the inputs sit in their own cells and the formula reads from them, the same setup answers a dozen related questions with a tweak, and Excel keeps every dependent figure current as the data changes. The tool above is there so you can rehearse and verify before committing anything to a real workbook; the steps and worked example are there so the logic sticks. Get it right once and it stops costing you time — it starts saving it, every time the question comes back around.

Common mistakes

• Forgetting the salvage value, which over-depreciates the asset below its real residual worth.
• Mixing methods within one schedule, so the totals no longer reconcile.
• Using DDB without a period argument that increments each year.
• Confusing accounting depreciation with the tax schedule your jurisdiction actually requires.

Frequently asked questions