1RM Calculator
Calculated in your browser — we never store your dataPeer-reviewed formulas (Mifflin-St Jeor, WHO)
Enter the number of reps completed with good form
This calculator provides estimates for informational purposes only. It is not medical advice. Consult a healthcare professional before making health decisions.
Training Load Chart
| % of 1RM | Weight | Rep Range |
|---|---|---|
| 100% | 212 lbs | 1 reps |
| 95% | 201 lbs | 2-3 reps |
| 90% | 191 lbs | 3-5 reps |
| 85% | 180 lbs | 5-7 reps |
| 80% | 170 lbs | 7-9 reps |
| 75% | 159 lbs | 9-12 reps |
| 70% | 148 lbs | 12-15 reps |
| 65% | 138 lbs | 15-18 reps |
| 60% | 127 lbs | 18-20 reps |
Training Goals by Percentage
90-100% (1-3 reps)
Maximum strength development. For experienced lifters only. Full recovery between sets (3-5 min).
80-90% (3-6 reps)
Strength and power. The sweet spot for building maximal strength with manageable fatigue.
70-80% (6-12 reps)
Hypertrophy (muscle growth). Most effective range for building muscle size.
60-70% (12-20 reps)
Muscular endurance and conditioning. Great for beginners and accessory work.
Safety Tip
Never attempt a true 1RM without a spotter. Use submaximal testing (3-5 rep max) and this calculator for a safer estimate.
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