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1-Rep Max (1RM) Calculator

Estimate your maximum single-repetition lift capacity and calculate training percentage breakdowns using Epley & Brzycki formulas.

Estimated 1-Rep Max (1RM)
115 kg

Rounded average of Epley and Brzycki estimates, not a measured maximum. Averaging the formulas does not guarantee greater accuracy.

Max Strength 90%+ · 104 kg
Hypertrophy 70–85% · 81–98 kg
Speed & Power 50–65% · 58–75 kg

Percentage Loading Guide

These percentages and repetition counts are rough planning references, not exclusive training zones or individual prescriptions.

Load Intensity Weight Est. Max Reps
95%109 kg~2 reps
90%104 kg~4 reps
85%98 kg~6 reps
80%92 kg~8 reps
75%86 kg~10 reps
70%81 kg~12 reps

Example Warm-Up Ramp

This automated example uses fixed barbell assumptions. Adjust the starting load, increments and rest to the actual exercise, equipment and your experience; it does not establish readiness for a maximal lift.

Set Intensity Load Reps Pacing / Rest
How this estimate is calculated

For load W and repetitions r, this tool calculates Epley as W × (1 + r / 30) and Brzycki as W × 36 / (37 − r). It averages the two and rounds to the nearest whole kg or lb. For one repetition, it uses the entered load directly.

For example, 100 kg for 5 repetitions gives approximately 116.67 kg and 112.50 kg. Their average is 114.58 kg, displayed as 115 kg. Percentage loads use that rounded estimate.

Research validates particular prediction methods in particular groups and exercises. A study of 18 elite male high-school powerlifters, for example, developed different equations for the squat, bench press and deadlift; it did not validate this tool's two-formula average.

The result depends on the set you enter and is specific to that exercise and technique. It is not a measured maximum or permission to attempt the predicted load. Use the exercise library to identify the movement rather than transferring an estimate between different lifts.

For Coaches & Bloggers: Embed this tool

Are you a personal trainer, coach, or fitness blogger? Embed this free, verified One Rep Max (1RM) Strength Calculator widget directly into your client portal or blog article with automatic responsive styling.