I cut mine to a length that left the rear wheel "light" on a flat, level garage floor. I don't remember how that lined up with any measurement markings on the legs.

In the real world, the smidge extra length made it easier to find a stable parking spot, especially on anything besides smooth concrete.

I'm not currently using mine since I got a simple Greenfield single-leg model that works fine, weighs less, and isn't finicky about exact length for good stability.