FREE TOOL

One Rep Max Calculator

Estimate your one-rep max from any working set. Use it to plan training percentages and track strength gains over time.

Weight Lifted

Reps Completed

208

lbs

%	Weight	Reps	Purpose
100%	208 lbs	1	Max Test
95%	198 lbs	2	Strength
90%	187 lbs	3-4	Strength
85%	177 lbs	5-6	Strength
80%	167 lbs	7-8	Hypertrophy
75%	156 lbs	9-10	Hypertrophy
70%	146 lbs	11-12	Hypertrophy
65%	135 lbs	13-15	Endurance
60%	125 lbs	16-20	Endurance

Uses Brzycki formula for 1-12 reps, Epley for higher rep ranges. Most accurate with 3-7 reps.

How to Use Your 1RM

Your one-rep max is the foundation of percentage-based training. Here's how to apply it:

Strength (85-95%) — Heavy weight, low reps (1-5). Builds maximal strength.
Hypertrophy (70-85%) — Moderate weight, moderate reps (6-12). Builds muscle size.
Endurance (60-70%) — Lighter weight, high reps (12-20). Builds muscular endurance.

Most programs mix these ranges. A typical week might include heavy squats on Monday (85%) and lighter volume work on Thursday (70%).

The calculator is most accurate with 3-7 rep sets. Higher rep sets introduce more fatigue variables.

Only count reps with clean technique. Grinder reps don't give accurate estimates.

Test when you're not fatigued from prior sets. Your first heavy set of the day is most accurate.

Retest every 4-6 weeks to keep training percentages accurate as you get stronger.

Let me build you a program that uses these percentages to drive real strength gains.