Orange County Floor Kitchen Bath

I’m remodeling my kitchen and want to save one of my wall cabinets.I have an air conditioner vent box that hangs about 7″ from the ceiling. The cabinet is 30″ long and there would only be 4″ between the bottom of the vent box and the top of the cabinet. Is that enough space? The reason that is the only space is because the refrigerator is below the cabinet.

Im looking for software that i can type in the dimensions of the room i want to lay down tile in, and then the size of the tile, so it can automatically plot the type of cuts i will need to make before i will actually start laying it down. This would save me alot of time. Thank You