How to Calculate Sum of Years Digits
What is Sum of Years Digits?
Sum-of-Years Digits (SYD) is an accelerated depreciation method that applies a declining fraction each year based on the sum of the years' digits. It is faster than straight-line but slower than double-declining balance.
Step-by-Step Guide
- 1SYD = n(n+1)/2 where n = useful life in years
- 2Year 1 fraction = n/SYD, Year 2 fraction = (n−1)/SYD, etc.
- 3Annual depreciation = (Cost − Salvage) × Remaining life fraction
- 4For 5-year life: SYD = 5+4+3+2+1 = 15; Year 1 = 5/15 = 33.3%
Worked Examples
Input
$50,000 asset, $5,000 salvage, 5-year life (SYD=15)
Result
Year 1: $15,000 | Year 2: $12,000 | Year 3: $9,000
5/15, 4/15, 3/15 of $45k depreciable base
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