One Rep Max Calculator
Estimate your one rep max (1RM) for any lift and get a full training weight table for every rep range.
How to use this calculator
Select your exercise, then use the sliders to set the weight you lifted and how many reps you completed. For best accuracy, use a weight where you completed 2-10 reps to near-failure. Your estimated 1RM updates instantly using three proven formulas averaged together, plus a full training weight table.
Understanding your 1RM
Your 1RM is the maximum weight you can lift for one complete rep with good form. Never attempt a true 1RM without an experienced spotter — use this calculator instead. The percentage table shows recommended training weights for different goals: 80-95% for strength, 65-80% for hypertrophy (muscle building), 50-65% for endurance.
Frequently asked questions
Training zones by % of 1RM
Different percentages of your 1RM produce different physiological adaptations. A well-designed strength program typically includes work across multiple zones throughout the week or training cycle.
| % of 1RM | Reps per set | Primary adaptation | Examples |
|---|---|---|---|
| 95–100% | 1 | Maximum strength, neural adaptation | Competition lifts, true 1RM testing |
| 85–95% | 2–3 | Strength, neuromuscular efficiency | Powerlifting, heavy compound sets |
| 75–85% | 4–6 | Strength + early hypertrophy | Strength-focused training blocks |
| 65–75% | 8–12 | Hypertrophy (muscle growth) | Bodybuilding, general fitness |
| 55–65% | 12–20 | Muscular endurance | Conditioning, circuit training |
| 40–55% | 20+ | Endurance, technique work | Warm-ups, rehab, skill practice |
The three 1RM formulas
All three formulas use weight lifted and reps completed to estimate 1RM. They are most accurate for sets of 2–10 reps — above 10 reps, all formulas become less reliable.
| Formula | Equation | Best accuracy range |
|---|---|---|
| Epley (1985) | 1RM = weight × (1 + reps/30) | 1–10 reps |
| Brzycki (1993) | 1RM = weight × 36 / (37 − reps) | 1–10 reps |
| Lombardi (1989) | 1RM = weight × reps^0.10 | 1–10 reps |
Standard 1RM benchmarks by lift
These are general strength benchmarks for adults relative to bodyweight. "Intermediate" is a realistic target for 1–2 years of consistent training.
| Lift | Beginner (M/F) | Intermediate (M/F) | Advanced (M/F) |
|---|---|---|---|
| Back squat | 0.75× / 0.5× BW | 1.5× / 1.0× BW | 2.0× / 1.5× BW |
| Deadlift | 1.0× / 0.75× BW | 2.0× / 1.25× BW | 2.75× / 1.75× BW |
| Bench press | 0.5× / 0.35× BW | 1.25× / 0.75× BW | 1.75× / 1.0× BW |
| Overhead press | 0.35× / 0.2× BW | 0.75× / 0.5× BW | 1.0× / 0.65× BW |
How to safely use 1RM estimates in training
Never attempt a true 1RM without an experienced spotter and a proper warm-up. Using estimated percentages from this calculator is far safer and equally effective for programming.
- ·Warm up with 40–60% of your working weight for 2–3 sets before heavy sets
- ·Use the 75–85% range (4–6 reps) for strength-focused training blocks
- ·Use the 65–75% range (8–12 reps) for muscle hypertrophy phases
- ·Re-estimate your 1RM every 4–6 weeks or whenever you hit a new working weight PR
- ·Log your lifts — systematic tracking is the only reliable way to see strength progress over time