How to Calculate Straight Line Depreciation?

How to Calculate Straight Line Depreciation?

Why use the straight-line method of depreciation? It represents the depreciation expense evenly over the estimated full life of a fixed asset. You can use a basic straight-line depreciation formula to calculate this, too.

Let’s break down how you can calculate straight-line depreciation step-by-step. We’ll use an office copier as an example asset for calculating the straight-line depreciation rate.

Step 1: Calculate the total cost of the asset

First and foremost, you need to calculate the cost of the depreciable asset you are calculating straight-line depreciation for. After all, the purchase price or initial cost of the asset will determine how much is depreciated each year.

Let’s say that an office worker purchases a copier for $8000. However, it costs another Rs.100 to ship the copier to the office. It also costs Rs.500 in taxes. The copier costs, in total, Rs.8600.

8000 + 100 + 500 = 8600

When you calculate the cost of an asset to depreciate, be sure to include any related costs. This can include material costs, labor, taxes, and more.

Step 2: Find and subtract any salvage value from the asset’s cost

With straight-line depreciation, you must assign a “salvage value” to the asset you are depreciating. The salvage value is how much you expect an asset to be worth after its “useful life”.

In the above example, say that the office worker expects the copier to be worth $2000 at the end of its useful life. The following calculation would look like this:

600 – 2000 = 6600

The salvage value of an asset is somewhat inexact. Try to use common sense when determining the salvage value of an asset, and always be conservative. Don’t overestimate the salvage value of an asset since it will reduce the depreciation expense you can take.

Step 3: Calculate the asset’s useful life

You’ll next need to calculate the useful life of an asset if you want to depreciate it. Common assets and useful lives include:

Office machines like copiers and fax machines – 5 years
Fixtures and office furniture – 7 years
Vehicles like cars and trucks – 5 years
Livestock, manufacturing tools, and tractors – 3 years

The IRS updates IRS Publication 946 if you want a complete list of all assets and published useful lives. Alternatively, you can estimate the useful life of an asset. But keep in mind that this opens up the risk of overestimating the asset’s value.

Step 4: Determine the annual rate of depreciation

You can determine the annual depreciation rate of an asset with the following formula:

1 / Years of useful life

If the above copier has a useful life of five years according to the IRS, the equation looks like this:

1 / 5 = 0.20

In other words, the copier can be depreciated by 20% each year.

Note that the straight depreciation calculations should always start with 1.

Step 5: Multiply your depreciation rate by the asset’s depreciable cost

The next step in the calculation is simple, but you have to subtract the salvage value. In our example, the copier cost Rs.8600 at first. It had a salvage value of Rs.2000. The annual depreciation rate is 20%.

The resulting calculation is:

20% x (8600 – 2000) = 1320

With this cancellation, the copier’s annual depreciation expense would be Rs.1320.

Step 6: Calculate monthly depreciation

Last but not least, you can calculate the monthly depreciation expense by taking the above number and dividing it by 12. You don’t have to stick with annual straight-line depreciation! For our example copier, the equation looks like this: