Before you ask what would be the best height to cut your grass, determine your grass type. Grass cutting heights are determined by the type of grass you're cutting. Different grasses such as Bahia can be cut between 2 1/2 to 4", Bermuda 1/2" to 2 1/2", St. Augustine between 2 1/2" to 3 1/2 ". Other conditions such as weather, location and time of year can also determine cutting height. Your deck pitch is fine.