One Rep Max Calculator
Estimate your 1RM from a submaximal lift and get a full training percentage table.
Your Lift
For best accuracy, use 2-10 reps. Stop the set before true failure if possible.
💪 Your Estimated 1RM
Average Across 3 Formulas
257
lbs
263
Epley
lbs
253
Brzycki
lbs
256
Lander
lbs
📊 Training Percentage Table
| % of 1RM | Weight (lbs) | Est. Reps |
|---|---|---|
| 100% | 257 lbs | ~1 rep |
| 95% | 244 lbs | ~2 reps |
| 90% | 231 lbs | ~3 reps |
| 85% | 219 lbs | ~4 reps |
| 80% | 206 lbs | ~5 reps |
| 75% | 193 lbs | ~6 reps |
| 70% | 180 lbs | ~8 reps |
| 65% | 167 lbs | ~10 reps |
| 60% | 154 lbs | ~12 reps |
| 55% | 141 lbs | ~15 reps |
| 50% | 129 lbs | ~20 reps |
Based on the average of Epley, Brzycki, and Lander formulas. Estimates are most accurate when original set was performed with 2-10 reps.
📖 Formula Details
Epley (1985)
263 lbs
1RM = w × (1 + reps/30)
Most commonly used formula. Works well across a wide rep range.
Brzycki (1993)
253 lbs
1RM = w × 36 / (37 - reps)
Popular in powerlifting. Most accurate in the 2-10 rep range.
Lander (1985)
256 lbs
1RM = (100 × w) / (101.3 - 2.671 × reps)
Designed to improve accuracy at moderate-to-high rep ranges.
Frequently Asked Questions
Which 1RM formula is most accurate?
No formula is perfectly accurate for everyone. The Epley formula is the most widely used and tends to be accurate for 2-10 reps. The Brzycki formula is popular in powerlifting circles. The Lander formula was developed specifically to improve accuracy at higher rep ranges. The average of multiple formulas gives a more reliable estimate.
How many reps should I use for the most accurate 1RM estimate?
Use 2-5 reps for the most accurate estimate. The formulas become less reliable as rep count increases beyond 10. At 15+ reps, muscular endurance factors in heavily and the estimate can be off by 20-30%. Avoid using sets taken to failure for estimation - stop 1-2 reps before failure for better accuracy.
How do I use my 1RM for programming?
Common training percentages: Strength (85-100% 1RM, 1-5 reps), Power (70-85%, 3-6 reps), Hypertrophy/muscle building (65-80%, 6-15 reps), Endurance (50-65%, 15+ reps). Programs like 5/3/1 and Texas Method use specific 1RM percentages to structure weekly progression.
Should I attempt a true 1RM?
Only with proper preparation and spotters. True 1RM testing requires a thorough warm-up, 3-5 build-up sets, and adequate rest between attempts. For most recreational lifters, using the calculated 1RM is safer and sufficient. Reserve actual max attempts for competitions or specific testing phases.
How often should I test my 1RM?
Calculated 1RM (from rep tests) can be done any training session. Actual 1RM testing is typically done every 8-16 weeks at the end of a training cycle. More frequent testing is unnecessary and fatiguing. Track your reps at given weights over time - seeing the numbers go up IS progress, even without formal testing.
How to Use
Enter the weight you lifted
Enter the weight of your recent lift - you don't need to go to failure. Use a weight you lifted for 2-10 reps for best accuracy.
Enter the reps you completed
Enter how many reps you performed. For most accurate estimates, use 2-5 reps. Avoid using high-rep sets (15+) for estimation.
Review your estimated 1RM
The average across 3 formulas gives you your best estimated 1RM. Individual formulas are shown for comparison.
Use the percentage table
The percentage table shows what weight to use at each intensity percentage, useful for structuring training programs like 5/3/1.