The 1-rep max is a great tool for anyone looking to increase their strength in the weight room.

It is an expression of strength in an exercise movement and an important way to track progress over time.

This article will explain what a 1RM is, why it is important, and how to use it in your exercise program for maximum results.

person lifting barbell with heavy weights
Manu Padilla/Stocksy United

A 1-rep max is the maximum amount of weight you can lift in a single repetition.

It is used to show strength and power in the exercise. It can help you estimate how much weight to lift in the future based on the number of reps.

For example, if you want to challenge yourself with 5 reps of back squats and you know your 1-rep max number for this exercise, you can simply calculate the weight to put on the barbell as 85–90% of your 1-rep max.

According to a review from 2020, finding your 1-rep max is a reliable test of overall muscular strength. This applies to different age groups, males and females, and single-joint or multi-joint exercises (1).

An older 2003 study determined that conducting a 1-rep max test is safe for healthy children and adults as long as they follow appropriate procedures — a finding that’s still cited by research today (2).

Summary

A 1-rep max is the amount of weight you can lift in a single exercise. It has been proven to be a reliable way to test strength.

Before you make the decision to test your 1-rep max in an exercise, you should consider a couple of parameters.

  • Safety. If testing your 1RM for a free-weight movement, it’s imperative that you use a good spotter — or at the very least a safety rack for barbell movements. When you fail, there needs to be something or someone to catch the weight to keep you safe from injury.
  • Technique. Pick an exercise you can do with good technique. As the weight gets heavier, it’s easy for your form to get sloppier. If the technique is not dialed in from the start, the tension can target your muscles and joints improperly, which can be dangerous and work against your goals.
  • Experience. A 2022 study found that 1RM testing was not ideal for beginners. Beginners don’t need to max out because their technique isn’t solid yet, which can be dangerous at high loads (3).

The following procedure is used to test your 1RM.

1: Warm up

Warm up with a weight that will comfortably do 6–10 reps with, which will be around 50% of your 1RM.

Rest for 1–5 min. How long exactly depends on when you feel 100% recovered and ready to complete the next step.

2: Increase the weight

You can increase the weight to a load by doing 3 reps with it.

Rest for a few minutes until you feel better.

3: Do your heaviest lift

Drop the number of reps to one. You can lift the heaviest weight with good technique. Continue to increase weight until you reach your limit.

You can lift for one rep once you reach the highest weight you can.

Alternative: use a different rep-max and estimate with a calculator

If you know your max amount of strength at a different range, you can estimate your 1-rep max.

The calculator below is used to estimate your 1RM based on your current personal records.

Access the calculator

“This calculator allows you to use a 10-rep max to estimate your 1-rep max. A true 1-rep max is more strenuous on the body and joints than a 10 rep-max. If you don’t have a spotter, it’s safer.”

The 1-rep max test will be more accurate than the calculated one. The 1-rep max may be higher or lower than what the calculator estimates.

Summary

To find your 1RM, you need to gradually increase the weight you use in an exercise and keep moving until you reach your limit. You can use a higher rep-max and a calculator to estimate your 1-rep max.

Knowing your 1RM is useful for athletes who compete in a strength sport.

In both powerlifting and Olympic weightlifting, the goal is to lift the most weight for just one rep. In other words, it’s fundamental to know your 1RM so you can decide which weights to lift in competitions and during practice.

You can use your 1RM to estimate which loads to lift in the gym. These numbers are only estimates and your personal percentages may vary between exercises.

Repetition percentages of the 1RM (4):

  • 100%
  • The max is 2rep max.
  • The max is 3-rep.
  • The max is 4-rep.
  • The max is 89%.
  • The max is 6rep max.
  • 7-rep max is 83%
  • The max is 81%.
  • The max is 9rep max.
  • 10-rep max is 75%.
  • The max is 11rep max.
  • The max is 12rep max.
  • The max is 13rep max.
  • 14-rep max is 68%.
  • 15-rep max is 70%.
  • The max is 16rep.
  • The max is 17-rep.
  • The max is 18rep max.
  • The max is 19rep max.
  • 20-rep max is 60.
  • The max is 21-rep max.
  • The max is 22-rep.
  • The max is 23 reps.
  • The max is 24 reps.
  • The max is 25%.
  • The max is 26 reps.
  • The max is 27 reps.
  • The max is 28 reps.
  • The max is 29-rep max.
  • 50% max.

You can standardize the loading by using percentages of 1RM. This will allow you to track improvements and manage your volume.

Summary

Knowing your current 1RM is important in strength sports. It can be useful for anyone in the gym to see their progress in a standardized format.

Studies show that your 1RM can help assess your strength regardless of your exercise selection.

A good way to capitalize on this is to pick a few major exercises to test your 1RM and to stick with those across your programming (1).

Strength is an exercise. Even if your bench press is less than 200 pounds, your overhead press or incline press will be different. Pick one movement to track per movement.

  • Bench press: chest/shoulders/triceps
  • Back squat: legs
  • Barbell row: upper/lower back

Then, use progressive overload over weeks to months. To ensure progress, use the percentages of your 1RM to figure out which weights to use based on the rep scheme you’re following.

You can estimate how much higher your new 1RM is by increasing the weight. You can re-test it.

An example of a strength program using percentages.

  • Week 1: Test your 1RM in the bench press, squat, and barbell row.
  • Week 2: Bench press, squat, and barbell row for 3 sets of 5 reps using 85% of your 1RM from week 1.
  • Week 3–5: Increase the weights in each exercise by 5–10 pounds (2.3–4.5 kg) each week.
  • Week 6: Either re-test your 1RM to gauge improvement or estimate it using your new five-rep max (5RM).

Summary

You can use your 1RM to ensure progressive overload. You can re-test your 1RM or use your 5RM to gauge your progress after 6 weeks.

“If you don’t want to re-test until the end of the training block, you should wait.”

Olympic weightlifting athletes often max out every four years, at the Olympics. You likely don’t need that long, though you should wait at least several weeks to months before re-testing to see if your training program is making you stronger. Adaptations take time.

The weights you use get heavier as you get stronger. Maxing out can be tiring for your joints. The risk of injury increases.

You can estimate your 1RM using the repetition chart above and gauge your progress that way, without having to perform 1RM tests again.

A 2020 study found that training with loads of 70–85% of people’s 1RM produced significant increases in 1RM. This means you can train at sub-maximal weights and still see strength gains (5).

Summary

Re-test your 1RM at the end of the training cycle. You can use your higher rep PRs to estimate progress.

If you’re interested in strength training, it can be useful to know your 1RM across different exercises.

It can help you determine your strength, progress, and weights to add in your training program.

It is best to wait for at least one training cycle before attempting a re- attempt. Try to overload your workouts to get stronger.