One-Rep Max Calculator

One-Rep Max Calculator | Sports Strength Training

Estimate your maximum strength for any lift using proven formulas and build training plans with ease.

Estimated 1 Rep Max (1RM)

Epley Formula:

Brzycki Formula:

Formulas Used

Epley: 1RM = weight × (1 + reps / 30)
Brzycki: 1RM = weight × (36 / (37 - reps))

Training Percentages Table

% 1RM	Weight	Target Reps*

* Typical reps possible at each percentage, actual numbers may vary by individual and exercise.

Strength Training Principles

Varying intensity (percentage of 1RM) allows for training different strength qualities, such as endurance, hypertrophy, or max strength.
Higher percentages (>85% 1RM) are primarily for low-rep strength work; moderate zones (~70-80%) target muscle growth and technique.
Track progress over time by periodically retesting your 1RM or using rep maxes (e.g., 3RM, 5RM).
Warm up properly, use spotters when appropriate, and never sacrifice form for heavier weights to avoid injury.

Safety Considerations

1RM attempts should be performed with supervision if possible, especially for beginners.
Online estimations are practical and safer alternatives for most lifters compared to actual max attempts.
If you have health issues or injuries, consult a medical professional before engaging in max strength testing.

About One-Rep Max (1RM) Calculators

Your one-rep max (1RM) is the maximum weight you can lift for a single repetition of an exercise with proper form. It serves as a benchmark for strength training progress and a reference for constructing effective workout plans.

Since performing actual 1RM tests can be risky (particularly for inexperienced athletes), prediction formulas like Epley and Brzycki are widely used. They allow you to estimate your maximum without having to perform single, maximal-effort lifts.