1RM Calculator

Calculate your One Rep Max and get training percentages for strength and muscle building

Calculate 1RM Training Guide

Calculate Your 1RM

Enter the weight you lifted and reps performed to calculate your maximum

Maximum reps with this weight

1RM Training Guide

50-70% 1RM
Speed & Power
  • Reps: 8-15
  • Purpose: Speed, power, warm-up
  • Rest: 2-3 minutes
  • Sets: 3-5
70-85% 1RM
Hypertrophy
  • Reps: 6-12
  • Purpose: Muscle growth
  • Rest: 2-3 minutes
  • Sets: 3-4
85-100% 1RM
Strength
  • Reps: 1-5
  • Purpose: Max strength
  • Rest: 3-5 minutes
  • Sets: 3-5

1RM Calculation Formulas

Formula Equation Best For Accuracy
Epley Weight × (1 + 0.0333 × reps) General use High
Brzycki Weight × (36 / (37 - reps)) Lower reps (1-10) Very High
Lombardi Weight × reps^0.10 Experienced lifters High

Safety Guidelines

Before Testing 1RM
  • Minimum 6 months training experience
  • Proper form mastered
  • Adequate warm-up
  • Have a spotter
  • Use proper equipment
When NOT to Test
  • When injured or sore
  • Without proper supervision
  • Poor sleep or nutrition
  • High stress levels
  • Beginning stages of training
Important Safety Notice

1RM testing should only be performed by experienced lifters with proper supervision and safety equipment. Always warm up thoroughly and use a spotter. These calculations are estimates - actual performance may vary. Consult a qualified trainer before attempting maximum lifts.