Santé & Fitness

One Rep Max Calculator

Estimate your 1-rep maximum for any lift based on the weight and reps you can currently perform.

For the most accurate estimate, use a rep count between 1 and 10.

Formulas Used

Estimated 1-Rep Max (1RM)
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Percentage Breakdown

Percentage Weight Est. Reps
Comment Utiliser
  1. Enter the amount of weight you lifted.
  2. Enter the number of reps you completed with that weight in a single set before failure.
  3. The calculator uses established formulas to estimate the maximum amount of weight you could lift for exactly 1 rep (your 1RM).
  4. Use the Percentage Breakdown table to program your workout sets (e.g., training at 80% for hypertrophy).

Formule

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

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

Lombardi Formula:
1RM = Weight × (Reps ^ 0.10)

Knowing your One Rep Max (1RM) is critical for strength training programs like 5/3/1 or Starting Strength, which base your daily lifts on percentages of your true max. Testing a true 1RM is dangerous and fatiguing; using a calculator based on a 3-5 rep max is much safer and highly accurate.