An asset's useful life is the period over which the business expects the asset to be available for its use, or the number of units of output it expects to get from it. It is one of the three estimates behind any depreciation schedule, with cost and salvage value.
Useful life is about your use, not how long the asset could physically last. A laptop may still work after six years, but if policy is to replace laptops every three, the useful life for depreciation is three years. For the units of production method it is expressed in hours, miles or units produced instead of years.
Useful life vs economic life vs physical life vs tax recovery period
| Term | What it measures | Set by |
|---|---|---|
| Useful life | How long this business expects to use the asset | Management estimate, reviewed each year (IAS 16) |
| Economic life | How long the asset can be used economically by anyone, across one or more owners | Market and technology; used in lease accounting |
| Physical life | How long it could keep working with maintenance | Engineering and condition |
| Tax recovery period | The period over which tax law lets you deduct the cost | Tax rules, such as US MACRS property classes |
How to estimate useful life
- Start with how you will use it. Shifts per day, distance per year, environment. A forklift on three shifts wears faster than one on one.
- Check your replacement policy and history. How long have similar assets actually stayed in service? Disposal records in the register answer this.
- Consider obsolescence. Technology, regulation or changes in demand can end an asset's usefulness before it wears out.
- Consider legal or contractual limits. A leasehold improvement cannot be used beyond the lease term, unless renewal is reasonably certain.
- Ask the people who maintain it. Maintenance history and manufacturer guidance help, but do not replace your own experience.
- Document the basis and apply the same life to similar assets through category defaults.
Illustrative useful lives
Organizations set their own lives. The figures below are examples of choices some policies make, not rules or recommendations:
| Asset class | Example policy life |
|---|---|
| Laptops and desktops | 3–5 years |
| Servers and network equipment | 5–7 years |
| Office furniture | 7–10 years |
| Vans and light vehicles | 4–8 years |
| Production machinery | 8–15 years |
| Buildings | 25–50 years |
| Land | Not depreciated |
Under IAS 16, significant parts of an asset with different lives are depreciated separately, for example a building's roof and lifts versus its structure.
Reviewing useful life (IAS 16)
IAS 16 requires useful life and residual value to be reviewed at least at each financial year-end. If expectations change, the change is a change in accounting estimate: past years are not restated, and the remaining NBV is spread over the remaining life.
Examples by sector
- Hospital: imaging equipment where useful life is set by expected clinical replacement, not by when it stops working.
- Construction: plant whose useful life varies with hours worked, which is why some fleets use units of production.
- School: classroom devices on a fixed refresh cycle, so useful life matches the cycle.
Common mistakes
- Copying tax recovery periods into the books without checking they reflect actual use.
- Never reviewing lives, leaving many fully depreciated assets still in heavy use. That is a sign lives were too short.
- One life for a whole category when usage differs widely between sites.
- Depreciating land, which normally has an unlimited life.
Spreadsheet vs software
A spreadsheet holds a life per row, but category-wide changes mean editing many rows and rebuilding formulas, and nobody can see which assets are still in use past their book life. Software applies category defaults, recalculates schedules when an estimate changes and reports assets near or past the end of their life. Model different lives in the free depreciation calculator.
Useful life in Asetavo
In Asetavo, useful life is set on each asset or as a default on its category, together with in-service date, method and residual value. Book and tax profiles can use different lives and methods. See Asetavo depreciation (Business plan).
