1.   Depreciation is calculated to write off the cost or valuation of tangible assets other than freehold land over their estimated useful lives.

2.   The difference is divided by the number of years of estimated life and the resulting figure deducted from revenue as an annual expense.

3.   The percentage is calculated to reduce the WDV to the scrap value over the estimated life of the asset.

4.   Now, companies are required to depreciate the value of their real estate over their estimated useful life.