Epley
High confidenceA practical general estimate with strong agreement in trained male athletes.
Student toolkit · Free calculator
Estimate 1RM without pretending one equation is perfect.
Compare eight established equations, see the spread, and use the result as one input into sensible loading decisions.
Recommended estimate116.6 kg
Bench press, male, 100 kg × 5. Range across all equations: 112.5–119.0 kg.
116.7 kg
Wathen
High confidenceA strong option across common gym-based repetition ranges.
Mayhew et al.
Moderate confidenceUseful in trained populations, with evidence supporting use in women.
Lombardi
Moderate confidenceA simple power-based estimate. Treat it as one view, not a definitive answer.
Reynolds et al.
Moderate confidenceA repetition-based estimate that sits comfortably within the comparison set.
O’Connor et al.
Moderate confidenceA conservative linear estimate that can be useful for planning.
Lander
Low confidenceHigher variability has been reported. Use the result with caution.
Brzycki
Low confidenceCommonly used, but can overestimate with greater repetition counts.