Muscle Recovery Calculator
Enter your workout to see per-muscle fatigue levels and estimate when each muscle group is ready to train again.
Quick Templates
Exercises
About the Fatigue Model
Set-Based Fatigue
Primary: 11% per set · Secondary: 5.5% per set
Each set performed as a primary mover adds 11% fatigue to the target muscle. Secondary muscles (assisting in the lift) receive 5.5% fatigue per set. This matches the model used by StrengthMaxxer for workout scheduling.
Rep Range Modifier
1-5 reps = 0.7x · 6-12 reps = 1.0x · 13+ reps = 1.2x
Heavy, low-rep sets cause less metabolic fatigue per set than high-rep sets. However, heavy sets cause more neural fatigue (not modeled here). High-rep sets produce more metabolic stress and muscle damage, increasing recovery needs.
Recovery Timeline
Fatigue decays linearly over a 48-hour recovery window. A muscle is considered “recovered” when it drops below 30% fatigue. For a typical workout, most muscles recover in approximately 24-34 hours. Factors like sleep, nutrition, age, and training experience also affect recovery but are not modeled in this calculator.