Formula Guide

The Excel SLN Function
explained simply

SLN calculates straight-line depreciation — spreading an asset's cost evenly across its useful life.

ExcelPro · 4 min read · Updated June 2026
Contents
  1. What does SLN do?
  2. Syntax
  3. 3 examples
  4. FAQ

What does SLN do?

SLN calculates the depreciation expense for one period under the straight-line method, which spreads an asset's loss in value evenly across every year of its useful life.

It is the simplest depreciation method: the same dollar amount is expensed every single period, unlike accelerated methods that front-load depreciation.

Syntax

=SLN(cost, salvage, life)
ArgumentDescription
cost requiredThe original cost of the asset.
salvage requiredThe estimated value at the end of its useful life.
life requiredThe number of periods (usually years) over which it depreciates.

Examples

Example 1
Annual depreciation of equipment
=SLN(10000,1000,5)

A $10,000 machine expected to be worth $1,000 after 5 years depreciates by $1,800 per year.

Example 2
Confirm total depreciation matches cost minus salvage
=SLN(10000,1000,5)*5

$1,800 per year over 5 years totals $9,000 — exactly the $10,000 cost minus the $1,000 salvage value.

Example 3
Depreciation of a vehicle
=SLN(35000,5000,7)

A $35,000 vehicle expected to be worth $5,000 after 7 years depreciates by about $4,285.71 per year.

Common mistakes

⚠️ Confusing straight-line with accelerated depreciation

SLN always gives the same amount every period. Methods like declining balance (DB) front-load larger depreciation in early years instead.

FAQ

Does SLN account for partial years?
No — it assumes full periods. Real-world asset depreciation schedules often need manual adjustment for assets purchased mid-year.

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