What is a One Rep Max (1RM)?

Your One Rep Max, or 1RM, is the maximum weight you can lift for a single repetition of a given exercise with proper form. It's one of the most important metrics in strength training and serves as the foundation for programming effective workouts.

Why Your 1RM Matters

Understanding your 1RM helps you:

Training Intensity: Calculate the right weight for different rep ranges. For example, 80% of your 1RM is typically used for 5-8 reps, while 65% works well for 12-15 reps.

Progress Tracking: Watching your 1RM increase over time is one of the best indicators that your training is working.

Program Design: Many effective strength programs are based on percentages of your 1RM, like 5/3/1, Wendler, and Texas Method.

How to Calculate Your 1RM

You don't need to actually test your 1RM to know it. Instead, use a proven formula based on a recent heavy set:

Epley Formula: 1RM = Weight × (1 + Reps / 30) Brzycki Formula: 1RM = Weight / (1.0278 - 0.0278 × Reps) Lombardi Formula: 1RM = Weight × Reps^0.1

For best accuracy, use a set in the 3-8 rep range. Sets above 10 reps become less accurate for 1RM estimation.

Example Calculation

Let's say you just benched 225 lbs for 5 reps. Using the Epley formula:

1RM = 225 × (1 + 5/30) = 225 × 1.167 = 262.5 lbs

This means your estimated 1RM for bench press is approximately 263 lbs.

Using Your 1RM for Training

Once you know your 1RM, you can program your training:

• Strength (1-5 reps): 85-100% of 1RM
• Hypertrophy (6-12 reps): 65-85% of 1RM
• Endurance (12+ reps): 50-65% of 1RM

Important Considerations

Don't Max Out Often: Testing your true 1RM is taxing on your nervous system and carries injury risk. Use calculated estimates instead.

Update Regularly: Retest or recalculate every 4-6 weeks as you get stronger.

Exercise-Specific: Your 1RM is different for each exercise. Track them separately.

Form Matters: A 1RM only counts if performed with proper form. Don't sacrifice technique for weight.

Track Your 1RM with Plate Progress

Plate Progress automatically calculates your estimated 1RM for every exercise based on your workout logs. You can see how your strength progresses over time with beautiful charts and automatic PR detection.

Ready to start tracking? Sign up for free and see your 1RM estimates for all your lifts!