One Rep Max Calculator
Estimates the most you could lift once from a heavier set of several reps, so you can plan training loads without testing a true max.
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The formula
Epley = weight × (1 + reps ÷ 30) Brzycki = weight × 36 ÷ (37 − reps) Lombardi = weight × reps^0.1 estimate = average of the three
Named after Boyd Epley, Matt Brzycki and V. P. Lombardi. A single rep counts as the weight lifted in all three. The typical reps in the table are a rule of thumb and vary with the lift and the person.
What to watch out for
Enter the weight and the reps from a set taken close to failure. The three formulas are averaged because no single one suits everybody: they agree closely at low reps and drift apart as reps rise.
Use the percentage table to pick training weights. Estimates are less reliable above about 10 reps, and they work better for barbell lifts than for machines or small isolation exercises.
Frequently Asked Questions
What is my one rep max from 100 kg for 5 reps?
Epley gives 116.7 kg, Brzycki 112.5 kg and Lombardi 117.5 kg, an average of 115.5 kg.
Which formula is the most accurate?
None is best for everyone. Studies find each one fits some lifts and lifters better than others, and they all lose accuracy above about 10 reps. The average is a reasonable middle figure.
Do I need to test a real one rep max?
Not for general training. Percentages from an estimate work well, and a hard set of 3 to 5 reps carries less risk than a maximal single. Competitive lifters test closer to a meet, with spotters or safety arms.