I can read/use scales, rulers, tapes, calipers, micrometers, dividers, telescoping gauges, bore gauges, vernier scales, framing squares, multimeters, thermometers, compasses, maps, height gauges, face clocks, and even books. But I'll admit, I don't have a clue without using google about how to measure my head for a hat.
You go to a place that sells fitted hats and pick the size that's comfortable for you.
