About the one-rep max calculator
Your one-rep max (1RM) is the most you can lift once. Testing it directly is demanding, so many lifters estimate it from a set of several reps. This calculator averages two widely used formulas and shows common training percentages.
How to use this calculator
- Enter the weight lifted.
- Enter the reps completed with good form.
- Read your estimated 1RM and percentages.
Worked examples
- Epley: 185 × 1.1667 = 215.8 lb
- Brzycki: 185 × 36 ÷ 32 = 208.1 lb
About 212 lb estimated 1RM.
Measurement guidance
Use good form
Only count reps completed with proper technique.
Frequently asked questions
Which formula is best?
They’re similar at low reps; averaging gives a reasonable estimate.
Is it safe to test a true 1RM?
It carries risk. Use a spotter, warm up, and consider coaching.