Why Track Your 1RM?
Your 1 Rep Max (1RM) is more than just a number—it’s the foundation for building every effective strength program. Knowing your true max lets you:
- Set the right weight for every exercise, every session—no more guessing!
- Break through plateaus by targeting intensity zones designed for real, measurable muscle and strength gains.
- Adjust your workouts with confidence using proven numbers, not old myths or random advice.
Why use our 1Rep Max Calculator?
Our calculator goes above and beyond:
- Choose from multiple proven equations: Select the formula that fits your training style or body type.
- Get instant training percentages: See how much to lift for every goal, whether you’re powering up for strength, building size, or hitting endurance targets.
- Track, chart, and compare: Log every lift, chart your progress over time, and spot trends that help you optimize every phase of your training.
Sign up free to unlock all features—because getting stronger should always be this smart (and easy). Leave the guesswork behind and build your own proven path to better gains!
Want proof of why 1RM testing matters? Check out the research on its reliability and benefits for all lifters in this peer-reviewed article: Reliability of the One-Repetition Maximum Test Based on Muscle Group and Gender.
Want the full story behind the One Rep Max and how it can transform your strength training?
Read our deep-dive article to discover its origins, expert tips, and how to use 1RM for powerful results.
Advanced 1Rep Max Calculator & Strength Tracker
Instructions (Click to expand)
- Enter what you lifted: Type in the exercise you performed (or choose it from the list), the exact weight you lifted, and the number of reps you completed.
- Pick your calculation method: Choose a formula for estimating your one‑rep max (1RM). If unsure, start with Epley.
- Click "Calculate 1RM": Instantly estimate your 1RM and see training percentages.
- Add notes & save: Write notes and click Save Progress. Your results stay saved and accessible.
Epley Formula
Most popular and accurate for 1-6 reps. Formula: Weight × (1 + 0.0333 × reps)
Your 1RM Results
Training Percentages
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Tips & Guidelines
🎯 Accuracy Tips
For the most reliable 1RM estimates, use weights allowing 3 to 8 repetitions per set, ensuring each rep is performed with strict form and near-maximal effort.
Avoid testing with very high reps (beyond 10), as fatigue and endurance factors reduce accuracy.
Always warm up thoroughly before any maximal or near-maximal lifts to prevent injury and improve consistency.
⚠️ Safety First
Never attempt a true 1RM without proper safety measures: use spotters, safety racks, or machines designed for maximal lifts.
If unsure, use submaximal lifts and estimate your 1RM with validated formulas.
Prioritize technique over load—lifting with poor form greatly increases injury risk.
📊 Training Zones
Base your training loads on percentages of your 1RM:
- Maximal Strength: 85–95% 1RM — 1–5 reps, heavy weight, long rests.
- Hypertrophy: 70–85% 1RM — 6–12 reps, moderate weight, moderate rests.
- Muscular Endurance: 50–70% 1RM — 12+ reps, lighter weight, short rests.