FitCalcLab

One-Rep Max Calculator

Estimate your 1RM from a set, with a % loading table.

Más preciso con 2-10 repeticiones cerca del fallo.

Estimación · 1RM

114.6 kg

Epley: 116.7 kgBrzycki: 112.5 kg

Porcentaje del 1RM (según el promedio)

% 1RMCarga (kg)Repeticiones típicas
100%1151
95%1092
90%1034
85%976
80%928
75%8610
70%8012
65%7415
Revisado por el FitCalcLab Editorial TeamActualizado el 2026-08-01Leer nuestra metodología

Cómo funciona la one-rep max calculator

Your one-rep max (1RM) is the most weight you can lift for a single repetition. Testing a true 1RM is risky, so most lifters estimate it from a set taken close to failure.

This tool shows two published estimates. The Epley formula (1985) is 1RM = weight x (1 + reps/30). The Brzycki formula (1993) is 1RM = weight x 36 / (37 - reps). Both are accurate for sets up to about ten reps and diverge as rep counts climb.

The percentage table below turns your estimated 1RM into working loads. It follows the standard strength-training relationship where roughly 85% of 1RM allows about 6 reps and 75% allows about 10.

  • Estimates are most accurate at 2-10 reps. Above that, error grows quickly.
  • Epley and Brzycki agree closely at low reps and separate as reps rise. Use them as a range, not a single true value.
  • Round working weights to the nearest plate you actually have.

Preguntas frecuentes