RPE & 1RM Autoregulation Calculator
Traditional 1RM calculators erroneously assume every set was performed to absolute muscular failure (0 RIR). This calculator integrates the RIR-based RPE scale per Zourdos et al. (2016) with Epley, Brzycki, and Wathan equations for precision load autoregulation.
1. Reference Set Just Performed
2. Target Parameter for Next Set
Personal RPE / RIR Load Table (in kg)
Exact projected weights (kg) across reps and RPE ratings based on your current estimated 1RM.
Peer-Reviewed Sports Science Foundations
This engine combines RIR-based effort anchoring with multi-formula failure extrapolation.
Journal of Strength and Conditioning Research: Confirms that RPE based on Reps in Reserve (RIR) provides significantly higher autoregulatory accuracy than Borg scale ratings in experienced strength athletes.
Validates algorithmic 1RM extrapolation from submaximal working sets: 1RM = Weight × (1 + Reps/30).
How does this calculator integrate RPE/RIR into 1RM estimates? +
Rather than counting only completed reps, it adds reps in reserve (RIR = 10 - RPE) to effective failure reps and applies the Epley formula: e1RM = Weight * (1 + (Reps + RIR) / 30).
What is the difference between Epley and Brzycki? +
Epley scales linearly and represents the gold standard in the 3-8 rep range. Brzycki provides a more conservative curve at higher repetition thresholds.
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