1RM Calculator
Estimate your one-rep max for any lift. Compare formulas and see why tracking your lifts improves strength gains.
Exercise name
Optional, just a label. 1RM calculation works for any lift
The six formulas
Epley: Simple and widely used, accurate for most lifters.
Brzycki: Better for moderate reps (2–10), commonly used in gyms.
Lombardi: Conservative estimate, useful for higher rep ranges.
Mayhew: Research-based, reliable for upper body lifts.
O'Conner: Easy multiplier, simple for quick calculations.
Wathan: Conservative formula, tends to slightly underestimate 1RM for safety.
Why Track Your Lifts?
- Tracking lifts consistently improves strength gains and prevents plateaus.
- Compare different formulas to understand realistic maxes for your lifts.
- Logging workouts lets AI provide actionable insights and progress tracking.
- Visualizing progress keeps motivation high.
Ready to track your lifts? Create a free account now.
FAQ
Which 1RM formulas should I use? ▼
- Epley: best all-around for most lifts and rep ranges.
- Brzycki: ideal for 2–10 rep sets, commonly used in commercial gyms.
- Mayhew: research-backed, especially reliable for upper body pressing movements.
- Wathan: conservative estimate, good when you want a safety margin.
How accurate is a 1RM calculator? ▼
- Most formulas are within 5–10% of your actual 1RM when reps are in the 2–10 range.
- Accuracy drops above 10 reps, lower rep sets give better estimates.
- Individual factors like fatigue, technique, and fibre type affect real-world results.
How do I use my 1RM estimate? ▼
- Set training loads as a percentage of your 1RM (e.g. 70–85% for hypertrophy).
- Track it over time to measure strength progress objectively.
- Use it to compare lifts across different bodyweights using tools like the DOTS calculator.
More tools: compare lifts across bodyweights with the DOTS calculator, or work out what to load with the plate calculator.