1RM Calculator — Estimate Your One Rep Max
Your 1RM (One Rep Max) is the maximum weight you can lift for exactly one repetition. It's the single most important number in strength training — and you never need to test it. Just enter a weight and the reps you completed.
Why Your e1RM Matters
Your estimated 1RM tracks strength progress even when the weight on the bar doesn't change. If you did 80kg × 8 last week and 80kg × 10 this week, your e1RM went from 101kg to 107kg. You got stronger — the e1RM proves it.
Epley vs. Brzycki: Both formulas have been validated for decades. Epley is more accurate at higher reps (10+), Brzycki at lower reps (3-5). This calculator averages both — the same method MUSCLE TECHNICS uses internally.
The Formulas
Epley (1985): 1RM = Weight × (1 + Reps / 30)
Brzycki (1993): 1RM = Weight × (36 / (37 − Reps))
Automatic e1RM Tracking
MUSCLE TECHNICS calculates your e1RM on every set, detects plateaus, and adjusts your weight in real-time.
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