Utility Box

1RM Calculator

Estimate your 1RM (One Rep Max) safely by inputting weight and repetitions, and check the training percentage table.

* 1RM estimation is most accurate for 1 to 12 repetitions. (Max 36)

Usage Tips

Plan your training weight without testing your true max

For lifts like the squat, bench press, and deadlift, testing a true one-rep max can be risky or tiring. Enter a weight you can lift for multiple reps to estimate your 1RM, then use the percentage table to plan strength, hypertrophy, or volume-based training sets.

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What is 1RM Calculator?

The 1RM Calculator estimates your One Repetition Maximum from sub-maximal sets and provides percentage-based training weights for safer, structured programming.

How to Use

  1. 1Enter a weight you can currently lift and your reps.
  2. 2Choose your unit (kg/lbs) and run the calculation.
  3. 3Review your estimated 1RM value.
  4. 4Use the 100% to 50% table to plan working sets by training goal.

Reference Knowledge

  • ●Epley formula: 1RM = Weight × (1 + Reps/30)
  • ●Brzycki formula: 1RM = Weight × 36 / (37 - Reps)
  • ●This tool uses the average of both formulas for a balanced estimate.

FAQ

Q.What is a 1RM and why is it important?

A.

1RM (One Repetition Maximum) is the maximum amount of weight you can lift for a single repetition with proper form. Knowing your 1RM is crucial for designing an effective and safe workout program, as it allows you to calculate specific training percentages for strength, hypertrophy (muscle growth), or endurance.

Q.What formulas does this calculator use?

A.

This calculator uses an average of the highly respected Epley and Brzycki formulas. These equations are widely used in sports science and powerlifting to provide the most accurate estimation of your 1 Rep Max.

Q.Do I need to lift my absolute maximum to find out?

A.

No! You can simply enter a sub-maximal weight you comfortably lift for 3 to 10 repetitions. The calculator will accurately predict your 1RM without the need for a dangerous max-out attempt. ⚠️ Warning: Attempting a true 1RM test can place immense stress on your joints and nervous system, carrying a high risk of injury. Beginners should always use a 1RM calculator to safely estimate their max and set appropriate training weights.

Q.Can beginners use a 1RM calculator?

A.

Yes. It estimates max strength from a manageable set, so beginners can avoid risky true-max attempts and use the result as a training reference.