Easy to figure out. Measure them with a 0-1" micrometer. Here are a couple inexpensive ones for sale at HF and NT. It's good to have at least a 0-1' in your tool box and a set of 6" dial or digital calipers are very handy as well.
Harbor FreightNorthern ToolsBetter quality ones will cost more such as Starrett or Mitutoyo.
StarrettMitutoyoBetter yet, beings you're not too far away, I'd be happy to measure them for you if you want to stop by some time.
John