Health & Body Suite
One Rep Max Calculator
Estimate your absolute strength limits (1RM) using lifting parameters and plan your structured warm-up loads safely.
1. Enter Lift Details
lbs
Lifts between 1 and 10 repetitions give the most accurate predictions.
Input Error Please provide valid variables.
Estimated One Rep Max (1RM)
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1RM Percentage Weights
95% (Approx 2 Reps): --
90% (Approx 4 Reps): --
85% (Approx 6 Reps): --
80% (Approx 8 Reps): --
75% (Approx 10 Reps): --
70% (Approx 12 Reps): --
60% (Approx 15 Reps): --
Recommended Warm-up
Set 1 (50% 1RM × 10): --
Set 2 (60% 1RM × 6): --
Set 3 (70% 1RM × 4): --
Set 4 (80% 1RM × 2): --
🏋️ Strength Estimation Formulas & Guidelines
A lifter's absolute strength capacity is commonly estimated rather than tested directly to decrease standard injury liabilities. These mathematical models predict the maximum single-repetition lift based on submaximal weight and repetition inputs.
Equations Epley & Brzycki
The two most popular linear regression models are defined as:
- Epley Formula: Built by strength researcher Boyd Epley, this linear approximation works exceptionally well for compound barbell movements:
1RM = Weight × (1 + Reps / 30) - Brzycki Formula: Proposed by Matt Brzycki, this equation utilizes a fractional reduction structure that represents fatigue levels:
1RM = Weight / (1.0278 - (0.0278 × Reps)) - Formula Selection: Both formulas provide reliable estimates. Averaging the two balances out variations, providing a robust estimate for training.