Training calculator

One rep max
calculator.

Estimate your one rep max from a recent working set. The calculator uses the same 1 to 30 rep percentage table used in the 531 app.

How to use this 1RM calculator

Enter the weight and reps from a hard, technically sound set. The result is an estimate, so use it as a reference point rather than a reason to test a maximal lift.

Using it for 5/3/1

5/3/1 begins with a conservative training max, normally 90% of your estimated one rep max. Enter that max in the 531 planner to see the rounded working weights for each week.

Build a 5/3/1 plan