One Rep Max Calculator
Calculate your estimated one repetition maximum for strength training
One Rep Max Calculator
Use this One Rep Max (1RM) Calculator to estimate the maximum weight you can lift for a single repetition based on the number of repetitions you can perform with a certain weight. For the most accurate estimate, please use a weight that you can lift between 1 and 10 times.
đī¸ââī¸ Lifting Parameters
đ 1RM Results
Training Percentages
Estimated Max Reps
| Repetitions | Weight | % of 1RM |
|---|
Training Percentages
| % of 1RM | Weight | Repetitions |
|---|
đ Understanding One Rep Max
What is One Rep Max?
A "one rep max" (one-repetition maximum) is the maximum weight a person can lift for one complete repetition of a specific exercise while maintaining proper form. It represents the peak force that a person's muscles can generate in an all-out effort.
Why 1RM is Important
Knowing your 1RM provides a quantitative measure of your maximal strength, enabling you to design effective workout programs, manage training intensity, track progress over time, and set improvement goals.
Safety Considerations
Using estimation methods is safer than directly testing your 1RM. Always prioritize proper form, use a spotter when possible, and consult with fitness professionals for comprehensive training guidance.
1RM Estimation Formulas
This calculator uses three popular formulas to estimate your one rep max:
Epley Formula
1RM = Weight à (1 + Reps/30)
Most popular and widely used
Brzycki Formula
1RM = Weight à 36/(37-Reps)
Good for moderate rep ranges
Lombardi Formula
1RM = Weight à Reps^0.10
Conservative estimation
Training Guidelines
Use your 1RM to design effective training programs based on your goals:
Power (50-60% of 1RM)
3-5 reps, 4-6 sets. Focus on explosive movement and speed.
Endurance (70% of 1RM)
10-15 reps, 4-6 sets. Build muscular endurance.
Hypertrophy (70-80% of 1RM)
7-12 reps, 3-5 sets. Optimal for muscle growth.
Strength (80-100% of 1RM)
1-3 reps, 3-4 sets. Build maximal strength. Use spotter!
â ī¸ Disclaimer
Always consult with a qualified fitness professional or healthcare provider before engaging in maximal strength testing or starting a new exercise program. Safety should be the top priority when assessing and training for maximal strength.