CZ
CalcyZone
everyday-health Verified Precision Tool

One Rep Max (1RM) Calculator

Estimate your 1RM maximum lift weight using Epley, Brzycki, and Lander formulas.

Mathematical Formula

Epley 1RM = Weight * (1 + Reps / 30)

Overview & Explanation

One Rep Max estimators project the maximum load a lifter can move for one rep based on multi-rep sets.

How It Works

  • Evaluates Epley and Brzycki strength equations based on weight and reps.

Practical Applications

  • Weightlifting training percentages.
  • Safe strength progression.

100 kg for 5 reps

Calculate Epley 1RM.

1

Calculate rep multiplier

1 + (5 / 30)

= 1.1667
2

Multiply by weight lifted

100 * 1.1667

= 116.7 kg 1RM

Frequently Asked Questions

Which 1RM formula is best for high rep sets?
The Brzycki formula is generally preferred for sets between 2 to 10 repetitions.