Depends on the weapon and other specifics… Typically 1 or 3. Most of the weapons I would typically carry don’t have a safety.
Some I carry on an empty chamber because it’s safer that way - like w/ an old Colt revolver with an integral firing pin. If I carry that weapon I have 5 rounds - the hammer is on an empty chamber.
HD (not in scope) weapons are the same way. Shotguns, like the Mossberg 500, are in ‘cruiser ready’ without a round chambered because they’re not considered ‘drop safe’.
Knowing the weapon you’re carrying and the specifics around the design, including potential shortcomings, allows for changing your carry posture to remain the most safe while doing so.