Brzycki Equation Calculator

1RM means “one rep maximum” – the heaviest weight you can lift for one perfect repetition.

Instead of testing this directly (which can be risky), the Brzycki formula lets you estimate it safely using lighter weights for multiple reps.

This keeps you safe while giving you valuable training information.

How the Brzycki Formula Works

The formula is simple and reliable:

How to Use Your 1RM for Better Workouts

Once you have your estimated 1RM, use percentages to plan your training:

• 60-70%: Building endurance and technique
• 75-85%: Building strength
• 85-95%: Developing power and speed

For example, if your 1RM is 200 pounds, train with 150-170 pounds for strength building.

There are several ways to predict your 1RM. Brzycki works well for most people doing 2-10 repetitions. Other formulas like Epley work better for higher reps (6-12), while McGlothin is good for endurance training (10+ reps). The Brzycki calculator shows you comparisons so you can see different estimates.

Why Formulas Aren’t Perfect

No formula gives exact results because everyone is different. Your genetics, how long you’ve been training, and recovery all affect your actual strength. The Brzycki formula is usually within 5-10% of your true maximum. Use it as a guide, not an absolute rule, and retest every few months to track progress.

Training Weight Ranges

• 60-75% of 1RM: Lighter weights for building endurance (8-15 reps)
• 75-85% of 1RM: Moderate weights for building strength (4-8 reps)
• 85-95% of 1RM: Heavy weights for power and maximal strength (1-4 reps)

Your training weight depends on your goals. For general strength, use 75-85% of your 1RM. Rest 2-3 minutes between sets for heavy weights, 60-90 seconds for lighter weights.

What Makes a Good Strength Level?

Strength is often measured as a ratio of weight lifted to body weight. For example, bench pressing 1x your body weight is good for most people. These ratios help set realistic goals regardless of your size. Your strength improves with consistent training, good nutrition, and adequate rest.

How to Track Your Progress

Use this calculator every 4-6 weeks to check your improvement. Beginners might see 5-10% gains per month, while experienced lifters see 2-5% gains. If progress stalls, check your training program, nutrition, and recovery. Remember that steady progress over time beats trying to rush results.

Formula Accuracy

Studies show the Brzycki formula is 95-98% accurate compared to actual maximum strength testing. It works well for 2-10 repetitions and has been tested on athletes and regular people alike. Research confirms it’s reliable for strength training planning.

Beginner Program

Train 2-3 days per week using 60-75% of your 1RM. Do 8-12 reps per set with 90 seconds rest between sets.

Intermediate Program

Train 3-4 days per week using 70-85% of your 1RM. Do 4-8 reps per set with 2-3 minutes rest between sets.

Advanced Program

Train 4-5 days per week using 80-95% of your 1RM. Do 2-5 reps per set with 3-5 minutes rest between sets.