Calculator
1RM calculator
From the weight you moved for a given number of reps, this calculator estimates your one-rep max (1RM) — using two established formulas plus their average.
Important
All results are estimates from published approximation formulas — not medical advice and not a diagnosis. If you have a medical condition, take medication, or are unsure, talk to your doctor first.
Before you test
Don't attempt a real 1RM test without experience and without safety measures (a spotter, safety pins). This estimate doesn't replace an actual maximal attempt — it's an approximation based on 2–10 cleanly performed reps.
Related reading
From numbers to a plan
The app turns your details into a weekly plan that keeps adapting to you — including a protein anchor and heart-rate zones in the running module. Sign in via email login (beta, free).
Go to the app (closed beta) →