1RM Calculator
Estimate your one-rep max from a submaximal set, compare common formulas, and see training percentages from 50% to 95%. Useful for programming when a true max test is unnecessary or impractical.
Inputs
Estimates become less reliable above 10 reps
Estimated 1RM
Average estimate
115.5 kg
Combined Epley, Brzycki, and Lombardi
Epley
116.7 kg
Brzycki
112.5 kg
Lombardi
117.5 kg
Training percentages
50%
57.8
60%
69.3
65%
75.1
70%
80.9
75%
86.7
80%
92.4
85%
98.2
90%
104
95%
109.8
Estimated 1RM is not a tested max. Use it as a programming guide.
What a 1RM estimate actually means
One-rep max is the heaviest load you can lift once with good form. Estimated 1RM uses formulas such as Epley, Brzycki, and Lombardi to infer that number from lighter sets. Estimates are practical, not exact.
Formulas diverge more as reps climb. A tough set of 3–6 is usually more informative than a set of 15. Fatigue, technique, and exercise selection all change the result.
Coaches often use estimated 1RM to prescribe percentages for hypertrophy, strength, and peaking blocks without asking every client to grind a true max.
Turn estimates into progression
ReGains helps coaches log workouts, track PRs, and keep progression visible so percentage-based plans stay connected to real training data.
Start using ReGainsRelated tools
FAQ
Which formula should I trust?
None exclusively. This tool shows multiple common estimates and an average. Use the range as guidance and confirm with training performance.
Is an estimated 1RM safe to test against?
Treat it as a planning aid. If you attempt heavy singles, use sensible warm-ups, spotters where needed, and stop when technique breaks down.