FREE TOOL
Find your one-rep max.
Enter a weight and how many reps you lifted it for. The calculator estimates the most you could lift for a single rep.
Unit
ESTIMATED ONE-REP MAX
Epley formula: weight × (1 + reps ÷ 30). Most reliable from 2 to 10 reps.
Training weights
Each percentage of your one-rep max, with roughly how many reps you could do at that weight.
How it works
Your one-rep max (1RM) is the heaviest weight you can lift once with good form. Testing it directly is tiring and carries more risk, so most lifters estimate it from a set of a few reps.
This calculator uses the Epley formula. It is most reliable from 2 to 10 reps; above that, the estimate drifts.
Stardo does this for every set.
Stardo estimates your one-rep max from every set you log and plans your next session around it. Join the waitlist to hear when it launches.