Every handgun has the caliber stated in the firearm itself. I can’t tell you what ammo/caliber without knowing which model Glock. Here is the link to Glock models: https://us.glock.com/en/pistols

If you leave us the model of your Glocks then we can help.

Bryan, (the easiest way is to simply look at the magazine caliber marking). Glock pistols will also have the caliber marked right on the slide as pictured here (9x19 = 9mm, .40 = 40S&W, .357 = 357 Sig, 10mm, 45ACP etc) : gunsweek.com/en/pistols/news/new-glock-43x-and-glock-48-pistols-now-rails

give us the model number and we can help