Amortisation

This applies to intangible assets such as patents or copyrights.
For example you acquire a patent for £20,00 with a useful life of 5 years.

AMORDEGRC

AMORDEGRC
Returns the depreciation of an asset in a single period (declining-balance method).
Amortized declining balance
depreciation factors
t < 3, factor = 1
t = 3 or 4, factor = 1.5
t = 5 or 6, factor = 2
t > 6, factor = 2.5

d0 = factor x cost x rate x yearfrac()
d1 = factor x (cost - d0) x rate
d2 = factor x (cost - d0 - d1) x rate
d3 = factor x (cost - d0 - d1 - d2) x rate

AMORLINC

AMORLINC
Returns the depreciation of an asset in a single period (linear method).

d0 = cost x rate x yearfrac()

d1 = cost x rate