How do you calculate your character's proficiency bonus?

Question

How do you calculate your character's proficiency bonus in D&D 5e?

Answer 1

Every class has the proficiency bonuses listed in the class table. It's 2 at level 1, 3 at level 5, 4 at level 9, 5 at level 13 and 6 at level 17.

If you want a formula instead, it's 1 + 1/4 level (round up).