YOu can buy dial calipers for less than $30.00 from several suppliers. Micrometers cost 4 times as much, and more, unless you haunt pawn shops, antique shops, and flea markets. It does not require a college degree to learn to read a micrometer, or caliper.
If money is that tight, ask around among friends and coworkers. Someone will have a micrometer, or caliper, and will either do the measuring for you, or show you how to "read" the tool, and use it correctly. I was under 10 years of age when my father first showed me how to use a micrometer, BTW. Dial Calipers have a large "DIAL" on them, with a needled that spins around as the caliper is opened and closed. There is a scale on the shaft of the caliper that is easily read.
If you don't have friends close by, stop by any machine shop and they will be happy to help you with a measurement. Many Auto repair shops also have micrometers and/or calipers on site.