1RM & Percentage Calculator
Calculate your true One-Rep Max in seconds from submaximal working sets, and generate instant 50% to 105% training load charts and custom percentages for your strength workouts.
Estimate your maximum single-rep capacity from any submaximal working set (1 to 10 reps) using the scientifically validated Epley and Brzycki equations.
Projected Rep-Max Targets (1RM to 12RM)
Calculate custom working percentages and access complete training load charts. Automatically synced with your 1RM, or enter your own custom benchmark weight.
Comprehensive Training Load Chart (50% to 105%)
| Percentage | Target Load | Rep Target | Training Zone & Focus |
|---|
What is a One-Rep Max (1RM) and Why is it Essential?
A One-Repetition Maximum (1RM) represents the absolute maximum weight you can lift for a single, fully executed repetition with proper biomechanical technique. In functional fitness, Olympic weightlifting, and CrossFit programming, strength training percentages (such as "5 sets of 3 @ 80% 1RM") are calculated directly from this benchmark.
How Does the Epley Formula Work?
Testing an actual maximal 1RM under heavy load introduces fatigue and elevates acute injury risk. The Epley formula safely estimates your maximum capacity from submaximal sets (between 2 and 10 repetitions) using the mathematical formula: 1RM = Weight × (1 + Reps / 30). For higher reps, we cross-reference this with the Brzycki equation to deliver balanced accuracy.
How to Apply Training Percentage Zones
- 50%–65% 1RM: Dynamic effort, barbell speed, technique refinement, and warm-up sets.
- 70%–80% 1RM: The sweet spot for high-volume Metcons, muscular hypertrophy, and functional strength endurance.
- 85%–95% 1RM: Heavy working sets designed to maximize neuromuscular motor unit recruitment and pure power output.
- 100%+ 1RM: Peak testing attempts, supramaximal holds, and new personal record (PR) milestones.
Frequently Asked Questions
For sets between 2 and 6 repetitions performed to near failure, the Epley formula boasts an accuracy rate of 95% to 98% compared to direct maximal tests, without the neurological exhaustion or injury risks of true max testing.
Percentage-based training (PBT) ensures you lift at precise intensities tailored to your specific adaptation goals. For example, lifting at 70%-80% builds muscular hypertrophy and volume, 80%-90% develops maximal strength, and 50%-65% develops bar speed and explosive power.
Yes. You can enter any weight lifted on dumbbells, kettlebells, leg press, or weighted pull-ups. The percentage calculator will determine your exact training loads for any exercise.
Yes, 100%. The WOD X mobile app lets you save and track lifetime progression curves for Squat, Clean & Jerk, Snatch, Deadlift, and Bench Press with secure offline cloud sync.