If you're serious about strength training, understanding your One Rep Max (1RM) is a powerful tool. It serves as a benchmark for progress, helps structure effective workout plans, and ensures you're lifting the right amount of weight for your goals. But knowing how to calculate your 1RM safely is crucial—poor execution can lead to injury and setbacks.

In this guide, we’ll explain how to determine your 1RM safely, the benefits of knowing it, the best formulas to use, and how to test it without risking your joints, muscles, or overall health.

What Is One Rep Max (1RM)?

Your 1RM is the maximum amount of weight you can lift for a single repetition of a given exercise with proper form. It’s most commonly used for compound lifts like the squat, deadlift, bench press, and overhead press.

Knowing your 1RM helps:

• Measure strength progress

• Customize workout intensity (via percentage-based training)

• Set realistic strength goals

• Prevent undertraining or overtraining

Why You Shouldn't Always Test It Directly

Testing your actual 1RM can be risky—especially if you're a beginner or returning after a break. It places your body under maximum stress, increasing the likelihood of injury if your form is compromised.

Instead, we recommend calculating it using a submaximal lift (lifting a lighter weight for multiple reps) and plugging it into a trusted formula. beställa anabola steroider diskret

Best Formulas to Calculate 1RM Safely

Here are three of the most accurate and commonly used formulas to calculate 1RM based on reps and weight lifted:

1. Epley Formula

1RM = Weight × (1 + (Reps ÷ 30))

Example: If you lift 100 lbs for 8 reps
→ 100 × (1 + 8 ÷ 30) = 126.6 lbs

2. Brzycki Formula

1RM = Weight × (36 ÷ (37 - Reps))

Example: 100 × (36 ÷ (37 - 8)) = 123.4 lbs

3. Lombardi Formula

1RM = Weight × Reps^0.10

Example: 100 × 8^0.10 = 122.6 lbs

Pro tip: For most users, the Epley formula is simple and highly accurate for reps under 10.

How to Calculate 1RM in 5 Simple Steps

Step 1: Choose a Compound Lift

Stick with exercises that involve multiple joints and major muscle groups:

• Barbell Squat

• Bench Press

• Deadlift

• Overhead Press

Step 2: Warm Up Thoroughly

Prevent injury by prepping your muscles:

• 5–10 minutes of light cardio

• Dynamic stretches for target muscles

• Gradually build up with lighter sets

Step 3: Select a Challenging Weight

Choose a weight you can lift for 4–8 reps with good form but that challenges you by the final rep. Avoid going to complete failure.

Step 4: Perform the Set

Focus on form. Do not rush. Stop if your technique breaks down.

Step 5: Plug Numbers Into a Formula

Use the weight and number of reps in one of the formulas above to estimate your 1RM.

1RM Chart: Quick Reference Guide

Reps	% of 1RM
1	100%
2	95%
3	93%
4	90%
5	87%
6	85%
7	83%
8	80%
9	77%
10	75%

This table allows you to estimate your 1RM by reversing the math. For example, if you bench 150 lbs for 6 reps, your estimated 1RM is:

150 ÷ 0.85 = 176 lbs

How Often Should You Recalculate Your 1RM?

For general training purposes, recalculate your 1RM every 6–8 weeks to track progress and adjust your training loads. Avoid frequent testing, especially maximal lifts, as they can cause nervous system fatigue or overuse injuries.

How to Use Your 1RM in Training

Once you have your 1RM, you can structure workouts based on percentages of that number:

• 50–60% 1RM: Light training, active recovery

• 65–75% 1RM: Hypertrophy (muscle growth)

• 80–90% 1RM: Strength and power

• 95–100% 1RM: Maximal effort (used sparingly)

Safety Tips When Testing or Calculating 1RM

• Use a spotter for lifts like bench press or squat

• Perfect your form before attempting heavy loads

• Avoid testing 1RM when fatigued or under-recovered

• Warm up thoroughly with progressive sets

• Listen to your body—don’t push through pain

Final Thoughts

Calculating your One Rep Max doesn’t have to be dangerous or intimidating. By using proven formulas, proper warm-ups, and calculated reps, you can estimate your 1RM accurately and safely. Whether you’re training for muscle gain, strength, or performance, your 1RM is a cornerstone metric that will help you train smarter and achieve better results over time.