Progression
Getting stronger is a bookkeeping job. You lift, you write it down, and next time you try to beat one number by a little: a rep, a small plate, a cleaner set at the same weight.
These pages set out the rules lifters use to decide that next number, with the arithmetic shown, so you can check each step against your own log.
Are one-rep max calculators accurate?
One-rep max calculators are close, not exact. Epley and Brzycki side by side from 2 to 12 reps, what studies found about error, and three rules for the number.
Double progression: reps first, then weight
Double progression explained with numbers. Add reps to the top of your range, then add the smallest plate. The rule as a table, a worked example, and the sums.
Progressive overload, explained with a log
What progressive overload is, five ways to add load ranked by how easy they are to write down, and one month of squats in a log with the sums done.