Skip to content
2x2xKit

One-Rep Max Calculator

Estimate your one-rep max from a lifted weight and rep count.

How this is calculated
Epley formula: 1RM = weight × (1 + reps/30)

Assumptions used in this calculation

  • Formula: Uses the Epley formula (1RM = weight × (1 + reps/30)), one of several common 1RM estimation formulas; results can differ slightly from other methods like Brzycki, especially at higher rep counts.

About this calculator

The one-rep max calculator estimates your theoretical one-rep max (1RM) using the Epley formula, from a weight lifted and the number of reps completed.

Worked example

100 kg for 5 reps

Result: Estimated 1RM ≈ 116.7 kg

Was this helpful?

Frequently asked questions

Related calculators

Lean Body Mass Calculator

Estimate lean body mass and fat mass from height and weight.

Protein Intake Calculator

Calculate your recommended daily protein intake based on weight and activity level.