I do not have just one EDC, I have maney and these are the calibers: .22 mag., 22 lr. .32 short, .32 long, .32 H&R Mag, 327 Federal magnum, .380 acp, .38 spl, .38 spl +P, .357 Mag, 44 spl, .44 mag, .40 cal, .44 Colt and last but not least, .357 Sig. I like choices. I also am old and have medical conditions that on some days limit me to certain guns and calibers.
I also collect knives, mostly pocket, so my EDC knife is also determined by need and size. I never have an excuse not to carry a gun and a knife because I have them small enough to fit into the waterproof pocket of my swim trunks and large enough to fit into a shoulder bag. Add Pepper spray, a small ASP Baton and tactical pen and I am well armed for an old guy. I do not know if my training from over 40 years ago will help me today, but I still remember a few things.