On Sep 8, 9:18 pm, Balan wrote:
Kindly tell me whether there is any formula or readymade function to find out
the number of years required to depreciate an asset fully ( minimum value $
1)using a declining balance method. For example, if my asset is worth $ 1000
now and it has to be depreciated at 10% / year i.e., value at the end of the
1st yr would be $900, second yr $810 and so on. I want the year to be
calculated until the value becomes $1 .

Try:

=1 + roundup(nper(-10%,0,-1000,1), 0)

or:

=1 + roundup((ln(1) - ln(1000)) / ln(1-10%), 0)