💪 1RM Calculator

1RM (One Repetition Maximum) is the maximum weight you can lift for a single repetition of a specific exercise with proper form. It's important because it helps you design effective training programs, track strength progress, and set appropriate training intensities for different goals.

1RM calculators provide estimates based on mathematical formulas. They are most accurate when using weights you can lift between 1-10 repetitions. The accuracy decreases with higher rep ranges (15+ reps). Direct testing is more accurate but carries higher injury risk.

Epley's formula is most commonly used and works well for most people and exercises. Brzycki may be more accurate for higher rep ranges, while Lander can be better for powerlifting movements. Try different formulas and see which aligns best with your actual performance.

Testing your actual 1RM carries injury risk and should only be done with proper warm-up, spotters, and preferably under supervision of a qualified trainer. For most training purposes, estimated 1RM values are sufficient and safer.

For beginners, every 4-6 weeks is sufficient. Intermediate lifters might test every 6-8 weeks, while advanced lifters may only need to test every 8-12 weeks or before competitions. Focus on consistent training rather than frequent testing.

While the calculator works for most compound movements (bench press, squat, deadlift, overhead press), it may be less accurate for isolation exercises or movements with different strength curves. It's most reliable for barbell compound movements.

1RM specifically refers to the maximum weight for one repetition, while PR (Personal Record) can refer to your best performance at any rep range (e.g., 5RM PR, 10RM PR). Your 1RM is your 1-rep PR.

Use percentages of your 1RM to determine training loads: 85-100% for strength (1-5 reps), 67-85% for hypertrophy (6-12 reps), and 50-67% for endurance (12+ reps). This helps ensure you're training at appropriate intensities for your goals.