One-Rep Max (1RM) Calculator
Estimate 1RM from weight × reps (Epley/Brzycki) and get training loads at 60–95%.
Your set
Estimated 1RM & training loads
| % of 1RM | Load |
|---|---|
| 60% | 158 lb |
| 65% | 171 lb |
| 70% | 184 lb |
| 75% | 197 lb |
| 80% | 210 lb |
| 85% | 223 lb |
| 90% | 236 lb |
| 95% | 249 lb |
Results interpretation
- 1RM is an estimate. It’s most accurate from sets of 3–10 reps performed close to failure.
- Method differences are small around 3–8 reps; Epley skews slightly higher at high reps.
- Use 60–75% for higher-rep volume, 80–90% for strength practice.
- Who it’s for: lifters planning training loads without maxing out every session.
How to estimate your 1RM safely
- Pick a recent set done with solid form, ideally 3–10 reps near failure.
- Enter the exact weight and reps, choose a formula, and select units.
- Review the estimated 1RM and training loads at 60–95%.
- Round to practical plate loads and plan sets across the week.
- Re-estimate periodically as strength changes.
How this calculator works
Formulas, steps & limits
We estimate your 1RM from a submaximal set. Choose a formula and enter the weight and reps you completed. The calculator applies:
- Epley:
1RM = w × (1 + r/30) - Brzycki:
1RM = w × 36 / (37 − r)
We then multiply the 1RM by common training intensities (60–95%) to produce a quick-reference table.
Assumptions & limitations: steady technique, full range of motion, near-max effort; very high reps (>12) and isolation lifts can reduce accuracy. Treat results as planning estimates.
Use cases & examples
Example 1 (Bench): 185 lb × 5 (Epley) → 1RM ≈ 216 lb. A solid heavy-triple target is ~85%: 183 lb.
Example 2 (Squat): 315 lb × 3 (Brzycki) → 1RM ≈ 334 lb. For volume sets at ~70%: 233 lb.
Example 3 (Kg press): 60 kg × 8 (Epley) → 1RM ≈ 76.0 kg. Technique practice at ~65%: 49.4 kg.
One-Rep Max (1RM) — FAQ
Which 1RM formula should I use?
Epley and Brzycki are both solid. Around 3–8 reps they give similar results—pick one and be consistent.
How accurate is a 1RM estimate?
Usually within a few percent for compound lifts done near failure with 3–10 reps.
Can I estimate 1RM from very high reps?
Estimates from >12 reps tend to overshoot. Consider testing a heavier, lower-rep set.
Should I round for plates?
Yes—round to practical loads (e.g., nearest 5 lb or 2.5 kg). Training precision matters less than consistency over time.
How often should I re-estimate 1RM?
Every 4–8 weeks or after a noticeable performance jump is a good cadence.
Does exercise choice matter?
Yes. Form breakdown and range of motion affect estimates. Compounds (squat/bench/deadlift) are most reliable.
One-Rep Max Calculator: Estimate 1RM, Set Smarter Loads, and Progress Without Maxing Out
A one-rep max calculator lets you translate everyday training sets into a clear estimate of your true strength. Instead of grinding risky maximal singles, you can take a normal set—say 5 reps at a challenging weight—then convert that performance into an estimated 1RM. From there, it’s easy to pick training loads at 60–95% of 1RM for volume, hypertrophy, and strength work. This approach reduces fatigue, preserves technique quality, and helps you progress more consistently across weeks and blocks.
Why estimate instead of test?
True max tests demand full recovery, a perfect warm-up, and unwavering focus. They also create high fatigue and carry more technical risk. Estimating from a tough set is faster, safer, and often more repeatable. When you use the same formula and rep range over time, trends in your estimated 1RM reflect meaningful strength changes with less noise from day-to-day variability.
Choosing a formula
Epley and Brzycki are widely used and behave similarly between three and ten reps. Epley tends to be slightly higher at high reps because it increases linearly with reps, while Brzycki grows more conservatively as reps climb. For most lifters, the critical point is consistency—pick a method that matches your training style and stick with it so week-to-week comparisons stay apples-to-apples.
Turning 1RM into training
The real power of a 1RM estimate is in planning. Loads around 60–70% are great for high-rep technique and volume work; 70–80% suits hypertrophy and strength endurance; 80–90% drives neural adaptations for strength; and occasional 90–95% singles sharpen skill for heavier attempts. Use the percentage table to anchor your sessions, then round to practical plate loads. Small day-to-day adjustments for bar speed and form are normal.
Improving estimate quality
- Log honest reps—count only full-ROM, controlled reps.
- Pick the right set—3–10 reps close to failure is the sweet spot.
- Mind the lift—compounds estimate better than small isolation work.
- Stay consistent—same formula, similar reps, comparable RPE.
Estimating your one-rep max isn’t about perfection; it’s about consistently better decisions. When load selection is grounded in a stable 1RM estimate, you’ll train hard enough to grow without constantly overshooting recovery. That’s how progress compounds.