1RM Estimator
Lift Details
LBS
REPS
Max 12 reps for accuracy.
Safety First: Never attempt a true 1RM without a spotter. This calculator lets you estimate it safely using sub-maximal weights.
Estimated One-Rep Max
0
Projected Max Strength
Epley Formula
1RM = Weight × (1 + Reps / 30)
Most accurate for recreational lifters.
Training Percentages
| % 1RM | Weight | Reps |
|---|
Training Zones
1
Strength (85-100%)
Low reps (1-5). Focuses on neural adaptation and maximal force production. Requires longer rest periods.
2
Hypertrophy (70-85%)
Moderate reps (6-12). The "bodybuilding" zone. Optimizes metabolic stress and muscle damage for growth.
3
Endurance (50-70%)
High reps (15+). Improves the muscle's ability to resist fatigue over time.