Depreciation Calculator
Depreciate any asset with five standard accounting methods: straight-line, 150% or 200% declining balance (with automatic switch to straight-line), sum-of-the-years’-digits, or units-of-production. Get a full year-by-year schedule for whichever method you choose.
Example: with Depreciation method Straight-line · Asset cost 40,000 · Salvage value 4,000 · Useful life 8 · Total units (production method) 180000 · Yearly units, comma-separated 30000,28000,25000,22000,20000,18000,20000,17000 · … → Year 1 depreciation: $4,500.
Computed by the calculator below using its default values. Change any input to see your own numbers.
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Every depreciation method allocates the exact same total amount — cost minus salvage value — over an asset’s useful life; only the timing changes. Straight-line is the simplest: an equal deduction every year. Declining balance and sum-of-the-years’-digits are “accelerated” methods that front-load larger deductions into the early years, which better matches assets that lose value or usefulness fastest when new — vehicles and technology being classic examples. Units-of-production ties the deduction to actual usage instead of the calendar, so a slow year produces a smaller write-off and a heavy-use year produces a larger one.
How it’s calculated
Straight-line: (cost − salvage) ÷ life, every year. Declining balance: book value × (factor ÷ life) each year, switching to straight-line on the remaining book value the first year that produces a larger deduction, and never depreciating below salvage value. Sum-of-the-years’-digits: (cost − salvage) × (years remaining ÷ sum of 1..life). Units-of-production: (cost − salvage) ÷ total estimated units × units produced that year. The partial-first-year option prorates year one by the % of the year the asset was in service, with the leftover spilling into one additional final year.
Results update as you type and are general accounting estimates, not tax advice — consult a tax professional for the depreciation method and convention required for your specific asset class.
Year-by-year depreciation schedule
Shows depreciation, accumulated depreciation, and book value for each year under your selected method.
Worked example
A $40,000 asset with a $4,000 salvage value and an 8-year useful life, depreciated straight-line, deducts a flat $4,500 every year until it reaches salvage value. The same asset under 200% declining balance deducts $10,000 in year one (25% of cost) and $7,500 in year two, tapering off from there. With a shorter life and a lower factor — say a 150% declining balance asset with no salvage value over 7 years — the method switches to straight-line partway through: years 1–3 use declining balance, then years 4–7 lock into an equal $6,063.23 straight-line deduction once that exceeds the shrinking declining-balance amount.
Common mistakes
- Forgetting that declining balance methods ignore salvage value in the rate calculation itself — the calculator only enforces the floor at the end, so the book value can approach but shouldn’t drop below salvage.
- Using a depreciation factor of 2 in the dropdown for “150% declining balance” — the factor should match the method (1.5 for 150%, 2.0 for 200%/double-declining).
- Mismatching the units-of-production total against the actual sum of yearly units entered, which causes the asset to fully depreciate earlier or later than the stated useful life.
Frequently asked questions
Do all methods depreciate the same total amount?
Yes — every method depreciates exactly cost minus salvage value over the asset's life. Only the timing changes: accelerated methods (declining balance, sum-of-years-digits) front-load the deduction into early years, while straight-line spreads it evenly.
Why does 200% declining balance switch to straight-line?
Declining balance depreciation shrinks every year, so late in an asset's life it can produce a smaller deduction than simply spreading the remaining book value evenly over the remaining years. Standard practice switches to straight-line the first year that would produce a larger write-off, ensuring the asset still fully depreciates to salvage value by the end of its life.
What depreciation factor should I use for double-declining balance?
Double-declining balance is simply 200% (a factor of 2) declining balance — the most common accelerated method. A factor of 1.5 (150%) declines more gently and is sometimes required for certain asset classes under U.S. tax rules; check current IRS guidance for which factor applies to your asset type.
When should I use units-of-production instead of a time-based method?
When an asset's wear tracks usage rather than the calendar — manufacturing equipment, vehicles measured by mileage, or machinery with a rated output capacity. It ties the deduction directly to actual units produced each year instead of assuming a fixed yearly pattern.
What does the partial first-year option do?
It prorates the first year's depreciation by the percentage of the year the asset was actually in service — for example, an asset placed in service halfway through the year gets 50% of a full year's deduction in year one, with the leftover half-year's worth of depreciation spilling into an additional final year.