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One Rep Max (1RM) Calculator

Calculate your estimated one rep max using four formulas (Epley, Brzycki, Lander, Lombardi). Enter weight and reps to get a full percentage chart for programming your lifts.

lb

Estimated 1 Rep Max

212.9

lb

Your set was at 87% intensity

Training percentages

Use this table to program sets. Based on your estimated 1RM of 212.9 lb.

Reps% of 1RMWeight (lb)
1 rep
100%
212.9
2 reps
95%
202.3
3 reps
93%
198
4 reps
90%
191.6
5 reps
87%
185.2
6 reps
85%
181
7 reps
83%
176.7
8 reps
80%
170.3
9 reps
77%
163.9
10 reps
75%
159.7
11 reps
73%
155.4
12 reps
70%
149

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What is a one rep max?

Your one rep max (1RM) is the maximum weight you can lift for a single repetition with proper form. It's the gold standard for measuring absolute strength and is used to set training loads across most strength programs.

The four formulas explained

No formula is perfectly accurate for every person. Individual factors like muscle fiber type, training age, and neural efficiency all affect how well submaximal effort converts to a true max. Using the average of all four formulas gives a more reliable estimate than relying on any single one.

  • Epley (1985): weight × (1 + reps/30). The most widely cited formula; tends to slightly overestimate at high rep ranges.
  • Brzycki (1993): weight × 36 / (37 − reps). More conservative; works best in the 1–10 rep range.
  • Lander: (100 × weight) / (101.3 − 2.67123 × reps). Often the most accurate in the 5–10 rep range.
  • Lombardi: weight × reps^0.10. Accounts for fatigue accumulation at higher rep ranges.

How to use your 1RM for programming

The percentage table below your result maps rep ranges to training percentages. Most programs, including 5/3/1, Texas Method, and Wendler, are built around percentages of 1RM. Common benchmarks:

  • 5 reps at ~87% — strength focus
  • 8 reps at ~80% — hypertrophy focus
  • 12 reps at ~70% — muscular endurance

For the most accurate estimate, use a weight and rep count you can perform with consistent form. 3–8 reps is the sweet spot.

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