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SYD Function

Q: What's the difference between SYD and SLN?

SYD uses accelerated method (higher early depreciation), SLN uses straight-line (equal annual amounts).

Excel 2007+

Summary

The Excel SYD function calculates depreciation using the sum-of-years' digits method, allocating higher depreciation amounts to earlier years of an asset's useful life. This accelerated depreciation approach matches expense recognition with higher early usage and wear.

Syntax

SYD(cost, salvage, life, per)

Parameters

Parameter	Type	Required	Description
cost	`Number`	Yes	Initial purchase price of the asset
salvage	`Number`	Yes	Estimated residual value at end of useful life
life	`Number`	Yes	Total number of periods (usually years) for depreciation
per	`Number`	Yes	Specific period number to calculate (1 to life)

Using the SYD Function

SYD implements the sum-of-years digits depreciation formula, where annual depreciation = (Remaining Life / Total Life) × Depreciable Amount. This method front-loads depreciation expenses, reflecting assets that lose value more rapidly in early years like vehicles or machinery.

Common SYD Examples

First Year Depreciation

=SYD(30000, 7500, 10, 1)

Calculates $4,090.91 depreciation for year 1 of a $30,000 asset with 10-year life and $7,500 salvage value.

Last Year Depreciation

=SYD(30000, 7500, 10, 10)

Calculates $409.09 depreciation for final year 10.

Monthly Depreciation

=SYD(50000, 5000, 60, 12)

Monthly depreciation for month 12 of 5-year (60 month) equipment lease.

Frequently Asked Questions

Both must use identical units - either years (annual depreciation) or months (monthly depreciation).

No, but returns #NUM! if per > life or per < 1.

SYD uses accelerated method (higher early depreciation), SLN uses straight-line (equal annual amounts).

Common Errors and Solutions

#NUM! error

Cause: Per argument exceeds life or is less than 1

Solution: Ensure 1 ≤ per ≤ life

#VALUE! error

Cause: Non-numeric arguments provided

Solution: All parameters must be valid numbers

Zero or negative life

Cause: Life parameter ≤ 0

Solution: Life must be positive number

Notes

Depreciable amount = cost - salvage
Formula: Depreciation = (life-per+1)/sum_of_years × (cost-salvage)
Sum of years calculated as n(n+1)/2 where n=life
Available since Excel 2007
Use DB function for declining balance method

Compatibility

Available in: Excel 2007, Excel 2010, Excel 2013, Excel 2016, Excel 2019, Excel 2021, Excel 365, Excel for Web

Not available in: Excel 2003, Excel XP, Excel 2000, Excel 97

Content last reviewed: December 9, 2025
Update frequency: As needed
Excel versions tested: Excel 2007+