One Rep Max Calculator
Estimate your one rep max (1RM) for any lift using weight and reps. Based on Epley, Brzycki, and other formulas.
Estimated 1 Rep Max
115.1
kg
Average of 4 formulas
Epley
116.7 kg
Brzycki
112.5 kg
Lander
113.7 kg
Lombardi
117.5 kg
Training load table (based on your estimated 1RM)
| % | Weight | ~Reps | Goal |
|---|---|---|---|
| 100% | 115.1 kg | ~1 | Max Strength |
| 95% | 109.3 kg | ~2 | Max Strength |
| 90% | 103.6 kg | ~4 | Strength |
| 85% | 97.8 kg | ~5 | Strength |
| 80% | 92.1 kg | ~6 | Strength/Hypertrophy |
| 75% | 86.3 kg | ~8 | Hypertrophy |
| 70% | 80.6 kg | ~10 | Hypertrophy |
| 65% | 74.8 kg | ~12 | Endurance |
| 60% | 69.1 kg | ~15 | Endurance |
About the One Rep Max Calculator
One Rep Max (1RM) is the maximum weight you can lift for exactly one repetition with proper form. Knowing your 1RM lets you set training loads scientifically: 60-70% of 1RM for hypertrophy (8-12 reps), 80-90% for strength (3-5 reps), 95%+ for peak power. Direct 1RM testing is risky - this calculator estimates it safely from your performance at higher rep ranges using the Epley formula.
Epley One Rep Max Formula
1RM = Weight × (1 + Reps / 30)
Weight = load lifted in kg · Reps = number of clean reps performed · Most accurate when tested at 3-10 reps range · Alternative: Brzycki formula = Weight × (36 / (37 - Reps)) · Percentages: 95% 1RM ≈ 2 reps, 90% ≈ 4 reps, 80% ≈ 8 reps, 70% ≈ 12 reps
Worked Example
Bench press: 80 kg for 6 clean reps
Estimated 1RM = 80 × (1 + 6/30) = 80 × 1.2 = 96 kg · 80% of 1RM = 76.8 kg (use for 8-rep hypertrophy sets) · 90% = 86.4 kg (use for 3-4 rep strength sets)
Tips & Insights
- 1
Test at 6-8 reps for the most accurate estimate - going to true failure at 1-2 reps has higher injury risk with little added accuracy.
- 2
The Epley formula overestimates 1RM for very high rep counts (15+). Use 6-10 rep range for reliable results.
- 3
Progressive overload: increase weight by 2.5-5% when you can complete the top of your rep range for 2 consecutive sessions.
- 4
Beginners should not test 1RM directly - estimate from reps until you have 6 months of consistent training.
- 5
Deadlift 1RM estimates are least accurate since technique fatigue matters more than muscular fatigue at higher reps.
Why this matters for you
Training without knowing your 1RM is like driving without a speedometer. It works, but you will inevitably be going too slow (not enough stimulus for adaptation) or too fast (overtraining and injury risk). Once you know your 1RM, programming becomes scientific: every set, every rep, every session has an intentional stimulus based on your actual capacity.
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