Get a dress makers tape. Start at the base of the horn against the skull and follow the growth of the horn along to the tip, thats the length. Measure the girth of the horn (around the base) against the skull, that is your second measurement. Do both sides and double the lesser of each measurement to get a total. All measurements are done in inches and 1/8" of inches.
There are finer details to the measuring than I have described, but this will give you an indicative figure.
Bookmarks