DDB

Syntax: DDB(C, S, L, P)

C = cost
S = salvage value
L = allowable life
P = the period for which the double declining depreciation allowance is being calculated

DDB returns the double-declining depreciation allowance given cost C, salvage value S, allowable life L, and N number of depreciation periods. The function is given by:

$$\frac{2 \times \mbox{\it bookvalue} }{ L }$$

where bookvalue is the current book value of the asset and L is the estimated life of the asset. The double declining balance depreciation allowance for the Pth depreciation period (DDB) is calculated by the following iteration formula, where BV is the book value for the ith depreciation period.

     BV$_0 = C$ 


for $i=1$ to $P$ do 

${\it DDB}_i = \max(2({\it BV}_i / L), 0)$ 

${\it BV}_i = \max({\it BV}_{i-1}­{\it DDB}_i, S)$

Examples:

DDB(200, 120, 25, 10) = 9.6

DDB(F9, F5, 10, 6) = 524.29, where F5 = $1800.00 and F9 = $8000.00

DDB(200, 220, 10, 7) = error!, must have ``cost'' $>$= ``salvage'' $>$= 0

Excel function: N/A