Measure him. Grab a tape measure. Measure the length of the main beams, all the tines and 4 circumference measurements on each antler. Add each antler up, add them together and then add the inside spread. That will be your gross. Subtract the two antler totals to get your side to side deductions. Subtract that from the gross to get the net. You should be able to have a score in about 15 minutes.