I set about making 5mm ID rings in 16 gauge round wire. I own a jump ring cutting system so the only distance between jump ring cut ends is the thickness of the blade. If cutting rings by hand with a flush cutter, you may want to go up a half or whole millimeter in jump ring size.
Next, three feet of 16 gauge square wire was twisted, annealed because twisting hardens the wire making it difficult to coil, and made into 5mm ID jump rings. They were too big! What happened? It stumped me for a bit until I realized that the distance catty corner on square wire means the wire will become a larger gauge when twisted. The rings were 14 gauge in size! Thank heavens I used only three feet of wire to start and the rings could be used in other projects.
Back to the drawing board! 18 gauge square wire was twisted and annealed to obtain 16 gauge rings! Who knew?! It must be in a book somewhere, but I did not go looking. Remember, I was "flying by the seat of my pants" here to make this bracelet!
Always make more jump rings that are needed just to be safe. After all, mistakes happen! This chunky chain would be great for men, but it would have to be made longer. Since men's chains generally do not have extender chains, the wrist it would be worn on should be measured for size.