GMAX measures how much impact a playing surface absorbs. A test device is dropped onto the field and records how quickly it stops. The lower the number, the more the surface is cushioning the athlete. The higher the number, the harder the field.
Why it creeps up
As infill compacts, migrates or gets lost, the surface gets harder. High-traffic zones usually climb first. Many programs aim to keep readings well under 165, and 200 is widely treated as the upper limit — but your turf manufacturer's warranty may set its own targets.
What to do with the numbers
Test at least once a year, and test the same spots each time so you can see trends. When numbers climb, the fix is usually maintenance: decompacting infill, topping up low areas and deep cleaning.
YourFieldIQ™ tracks GMAX results quarter over quarter alongside cleanings and repairs, so you can show your board exactly how the field is holding up.
See the one-pass deep clean