You can only depreciate office furniture.
Depletion and depreciation are similar terms. Depletion is commonly referred to for the use of a resource, like coal, whereas depreciation means the use of an asset. However, both words perform the same function. You start off with the cost of an item and, over the life of that item, you have an expense to match its use. With furniture, you should use depreciation. The two most common depreciation forms are straight line depreciation and double declining depreciation.
Find the cost of the furniture, and estimate a useful life for the furniture and if you think it will have any value when you are done with it. The useful life is how long you reasonably expect the furniture to last. For example, assume you bought furniture for $500 and expect it to last for five years and it will be worth $50 at the end of the five years.
Subtract the value you estimate the furniture to be worth at the end of its useful life from the cost of the furniture. Then divide the difference by the useful life to depreciate the asset under straight line depreciation. In the example, $500 minus $50 equals $450. Then, $450 divided by five years equals $90 of depreciation a year.
Divide two by the useful life of the furniture and then multiply the result by current value of the furniture to calculate depreciation using the double declining depreciation method. The current value of the furniture is the cost of the furniture minus any accumulated depreciation. In the example, two divided by five years equals 0.4. Then, 0.4 times $500 equals $200 of depreciation for the year.
McBride, Carter. "How to Calculate Furniture Depletion." Small Business - Chron.com, http://smallbusiness.chron.com/calculate-furniture-depletion-10012.html. Accessed 22 April 2019.