DDB

Returns the calculated the depreciation allowance on an asset at a specific period of time using the double declining balance method.

Syntax:

DDB(cost:number, salvage:number, life:number, period:number {, factor:number})

costis the original value,
salvageis the value at the end of the life,
lifeis the number of periods for which you want to calculate the depreciation allowance,
periodis the period for which the depreciation is being measured.
factoris the rate at which the balance declines. Default is 2.0.

Example:

DDB(5000, 1000, 5, 1)

returns the number 2000 (pounds), the value of a £5000 asset with a salvage value of £1000 one year into its five-year depreciation.