There are a few different ways that hatch clearance can be measured. The most common way is to measure from the top of the door opening to the top of the highest point on the roof. This measurement is typically taken with the door open and the vehicle on level ground. Another way to measure hatch clearance is from the bottom of the door opening to the top of the highest point on the roof. This measurement is typically taken with the door closed and can be affected by things like suspension height and tire size. The last way to measure hatch clearance is from the ground to the top ofthe highest point onthe roof. This measurement is taken withthe vehicleon level ground and can also be affected by things like suspension height and tire size.