## Straight-line depreciation:

Under the straight-line depreciation method, the cost of an asset is gradually decreased over its life. The depreciation charged yearly is calculated by dividing the difference of expected salvage value and original cost by the useful life of the asset.

Calculation of depreciation for the current year:

{eq}\begin{align*}{\rm\text{Depreciation}}\;{\rm\text{expense }} &= \dfrac{{{\rm\text{Original}}\;{\rm\text{cost}}}}{{{\rm\text{Useful}}\;{\rm\text{life}}}}\\ &= \dfrac{{\$250,000}}{{5\;{\rm\text{years}}}}\\ &= \$ 50,000\end{align*} {/eq}

The depreciation expense under the straight-line method when the mid-quarter convention applies is \$50,000.