What is the Sum-of-Years-Digits method?

SYD is an accelerated depreciation method. It assigns higher depreciation expense to the early years of an asset's life by using a decreasing fraction each year. The denominator is the sum of all year digits: for a 5-year asset that is 1+2+3+4+5 = 15.

How is the SYD fraction calculated each year?

In year Y of an asset with N-year life, the fraction is (N - Y + 1) / [N(N+1)/2]. For example, year 1 of a 5-year asset uses 5/15, year 2 uses 4/15, and so on down to 1/15 in year 5.

What is the depreciable base?

The depreciable base is the asset cost minus the salvage value. Only this amount is depreciated; the salvage value is never expensed.

When should I use SYD instead of straight-line?

Use SYD when an asset is more productive (or loses value faster) in its early years, or when you want to accelerate tax deductions. Straight-line is simpler and spreads cost evenly; SYD better matches expense to economic benefit for assets that wear out quickly.

What is the book value at the end of useful life?

Book value at the end equals the salvage value. The SYD method is designed so that accumulated depreciation exactly equals the depreciable base (cost minus salvage) by the final year.

Is SYD accepted under GAAP and IFRS?

Yes. Both GAAP and IFRS allow the Sum-of-Years-Digits method as long as it reasonably reflects the pattern in which the asset's economic benefits are consumed.

Sum of Years Depreciation Calculator

Name: Sum of Years Depreciation Calculator
Availability: InStock
Author: Nham Vu

Enter asset cost, salvage value, and useful life to get a full SYD depreciation schedule with annual amounts and book values.

Asset Details

Asset Cost ($)

Salvage Value ($)

Useful Life (years)

Enter asset details and click Calculate to see the full SYD depreciation schedule.

SYD Depreciation Schedule

Year	SYD Fraction	Depreciation	Accum. Depr.	Book Value

Summary

Enter asset cost, salvage value, and useful life to get a full SYD depreciation schedule with annual amounts and book values.

How it works

Enter the asset's original cost (purchase price).
Enter the expected salvage (residual) value at end of useful life.
Enter the useful life in years (1 to 40).
The calculator computes the SYD denominator: n(n+1)/2.
Each year's depreciation = (remaining life / SYD) x depreciable base.
The full schedule shows depreciation, accumulated depreciation, and book value for every year.

Use cases

Accounting: record accelerated depreciation for machinery and equipment.
Tax planning: front-load deductions to reduce taxable income in early years.
Financial modeling: project asset book values over time.
Comparing depreciation methods (SYD vs. straight-line vs. declining balance).
Business valuations that require accurate net book value at any point.
Capital budgeting and asset replacement analysis.
Preparing GAAP or IFRS financial statements.
Explaining depreciation schedules to clients or stakeholders.

Frequently Asked Questions

Last updated: 2026-07-01 · Reviewed by Nham Vu