calcolatore.online
ESIT
ITENES

One Rep Max (1RM) Calculator

Estimate your one-rep max from weight lifted and repetitions. Epley and Brzycki formulas with training percentage breakdown.

Sources: Epley B. -- Poundage Chart, Boyd Epley Workout, 1985 · Brzycki M. -- Strength Testing, JOPERD 1993 · NSCA -- Essentials of Strength Training and Conditioning

Sponsored content — Affiliate links. If you purchase through these links, we may earn a commission at no extra cost to you.

How the One Rep Max (1RM) Calculator Works

This tool estimates your one-rep max (1RM) from the weight lifted and number of repetitions completed, using the two most recognized formulas in strength training: Epley and Brzycki.

The Calculation Formulas

Epley Formula (1985): 1RM = Weight x (1 + Reps / 30)

Brzycki Formula (1993): 1RM = Weight x 36 / (37 - Reps)

For example, if you lift 80 kg for 8 reps:

  • Epley: 80 x (1 + 8/30) = 101.3 kg
  • Brzycki: 80 x 36 / (37 - 8) = 99.3 kg

Training Percentage Table

% 1RMRepsGoal
90-100%1-3Max strength
80-90%3-6Strength
70-80%6-10Hypertrophy
60-70%10-15Muscular endurance
50-60%15-25Endurance, technique

Tips for Accurate Testing

For the most precise estimate, use a set of 3-6 reps with a challenging but manageable weight, maintain perfect form, test when fresh, and update your max every 4-6 weeks.

Sponsored content — Affiliate links. If you purchase through these links, we may earn a commission at no extra cost to you.

Frequently Asked Questions

What is the one-rep max (1RM)?▼
The 1RM (One Repetition Maximum) is the maximum weight you can lift for a single rep with correct form. It is the standard measure of maximal strength. The Epley and Brzycki formulas estimate it from a submaximal set without the injury risk of actual max testing.
What is the difference between Epley and Brzycki?▼
Both are validated formulas. Epley (1RM = weight x (1 + reps/30)) tends to give slightly higher values with many repetitions. Brzycki (1RM = weight x 36/(37-reps)) is more conservative and often considered more accurate with 4-7 reps. The average of both is a good compromise.
How do I use the 1RM to program training?▼
The 1RM serves as a base to calculate training loads: 90-100% for maximal strength (1-3 reps), 75-85% for strength and hypertrophy (6-8 reps), 65-75% for hypertrophy (10-12 reps), 50-65% for muscular endurance (15-20 reps). Update your 1RM every 4-6 weeks.