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1RM Calculator
Enter the weight you lifted and the number of reps to estimate your one-rep max across three proven formulas.
Enter Your Lift
How It Works
This calculator uses three widely accepted formulas to estimate your one-rep max (1RM) from a submaximal effort:
- Epley —
weight × (1 + reps/30). The most commonly used formula and the default in many training apps. - Brzycki —
weight × 36/(37 − reps). Tends to be more conservative, especially at higher rep ranges. - Lander —
weight × 100/(101.3 − 2.67 × reps). Falls between Epley and Brzycki for most inputs.
All three formulas lose accuracy above 10–12 reps. For the most reliable estimate, use a weight you can lift for 3–8 reps with good form.
Why It Matters
Knowing your 1RM helps you program training percentages accurately—the foundation of structured strength training. SensAI uses your performance and recovery context to generate progressive plans that adapt weekly.
SensAI programs your percentages automatically
Connect your health data and let AI generate progressive training plans that adapt weekly based on your performance and recovery.
