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Sum-of-the-Years-Digits Depreciation Calculator

What do the numbers come to once the work is shown?

Sum-of-the-years-digits expense for any year, accumulated depreciation and book value from cost, salvage and useful life.

  • Runs in your browser
  • Nothing stored or sent
  • Free, no sign-up
Your figures
Example figuresIllustrative only. Type over them with your own.
Depreciation for the year shown
$22,400
Depreciable base times remaining life over the digit sum
Accumulated depreciation
$50,400
Book value at year end
$39,600
Drawn to one scale
Depreciation for the year shown$22,400
Accumulated depreciation$50,400
Book value at year end$39,600
All results
MeasureResult
Depreciation for the year shown$22,400
Accumulated depreciation$50,400
Book value at year end$39,600
Sum of the years digits15.00
Fraction applied this year26.67%
How this was worked out
Work shownrecomputed as you type
Digit sum = n x (n + 1) / 2
Expense in year t = (cost - salvage) x (n - t + 1) / digit sum

Illustrative arithmetic on the figures you enter. Check the result against your firm's methodology before relying on it.

The formulas

  • Digit sum = n x (n + 1) / 2
  • Expense in year t = (cost - salvage) x (n - t + 1) / digit sum

How it works

Sum-of-the-years-digits is an accelerated method. Each year takes a fraction of the depreciable base whose numerator is the remaining life, so the fractions step down by one digit a year. For five years the digit sum is 15 and year one takes 5/15.

Unlike declining balance, the fraction is applied to cost less salvage, so the schedule lands exactly on salvage in the last year with no plug. Fiscal years that do not match the asset year need a time-weighted split of two asset years.

Illustrative figures only. Check the result against your firm's methodology before relying on it.

Common questions

Is the schedule always exactly salvage at the end?

Yes. The fractions add to 100 percent of the depreciable base.

What about a mid-year start?

Weight each asset year across the two fiscal years it touches.

Is this allowed for tax?

This tool is for book depreciation only.

Formulas on this page are the standard definitions.

Runs in your browser. The figures you type are not sent to CORAA or stored. Check the result against your firm's methodology before relying on it.

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