measurements are pointless in this case...visuals arent.
realize that the bulk of the muscle bellies are found in the upper thigh (hams, quad) and your vmo being in the lower thigh.
now...if you have a dinky vmo, thats one thing, but dont let the tape measure delude you that you should have symmetrical upper and lower thigh measurements. let simple anatomy tell you why the 2 measurements arent quite equal.