Rental property depreciation calculators are a useful tool for helping to understanding how your big purchases and improvements can save you lots of money. We DO recommend though, for ACTUAL depreciation calculations, that you use a CPA or tax professional to make sure you structure your rental property tax returns in the best possible way for your unique financial situation. Different types of expenditures will require a different number of years to span out your deductions. For instance, the depreciation for the purchase of the actual rental property will span over the "useful life" of the property (as set by the IRS, currently 27.5 years). However, the deduction for having a new roof installed will be carried over a shorter length of years.
Expenses of your rental property are sorted into two main buckets, according to the IRS: same-year type deductions, where they consider the expense to be "used up" in that same year. These expenses include property taxes, mortgage interest, repairs, maintenance and similar expenses. These deductions would be taken in the same year they are paid for.
But what about the actual purchase of the rental property itself? Or installing a brand new roof, or adding a room etc? The IRS considers those types of expenses to be "useful" over multiple years. So for instance, you may have just paid $15k to have a new roof installed on your rental property in 2016. The IRS