Free calculators built on the same maths as the PRE SZN app.
Estimate your 1RM from any set — the same Epley/Brzycki/Wathan model the app runs — with a full %1RM loading table.
Estimated 1RM from a set rated by RPE or reps in reserve, plus working weights for any rep and RPE target.
Pace per km and mile from any run, plus Riegel race predictions for 5K, 10K, half and marathon.