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One Rep Max Calculator

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How it works

Epley formula: 1RM = weight × (1 + reps/30). Brzycki: 1RM = weight / (1.0278 − 0.0278 × reps). Most accurate for 3–10 reps; less reliable above 12 reps. Use 1RM to set training percentages: strength work at 85–95%, hypertrophy at 65–85%, endurance below 65%. Actual 1RM varies with fatigue, technique, and daily readiness—test in controlled conditions.

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