Jeff, check to see if there's a local Harbor Freight store near you. They've got some cheap digital calipers on sale for a whole ten bucks. Not the world's finest but at that price, a handy thing to have. You'll be measuring OD and new hose may be sold by ID, so if you can't just cut off a piece and take to the store to match up--at least make sure you order from a live human and let them know you're measuring OD-vs-OD and need them to confirm the ID matches.
(I'm not a big Harbor Freight, China's Finest fan, but sometimes, you can't get too badly burned for ten bucks!)