Unfortunately, there is no single answer to that question. It depends on how fast your grass is growing and how tall that particular type of grass is at its healthiest, but a good rule of thumb to maintain the health of your lawn is to never cut more than one third of the grass height at one time. The turf experts at Affinity Landscaping are extremely knowledgeable about local grasses and turf types and how to keep them healthy but well-trimmed and maintained.