I am trying to calculate the potential gain on the sale of my rental property. I know the original cost, the depreciation taken, etc. What else is included in the adjusted basis?

Selling expenses such as real estate sales commission, advertising and attorney fees can be added to you original cost basis for determining capital gain/loss.

In addition, capital improvements such as a new roof, driveway or complete replacement to the physicial structure (rather than just a repair) can also be added to basis.

If you started with vacant land, then costs such as engineering fees, survey fees, and demolition of a prior structure are costs which are added to the original land basis.

I would spreadsheet all capitalized costs, prior depreciation and then report on the tax return.

Good luck.