One Rep Max Calculator – How to Calculate Your One Rep Max for Lifting

This guide will help to show you how to calculate and improve your one rep max.

What Is Your One Rep Max?

The phrase literally means “one repetition maximum”.

It is a commonly used technique to identify and measure strength levels of athletes across different lifts for bodybuilders, powerlifters, CrossFit® athletes and bodybuilders.

It stands as an excellent and objective measure of strength, and you should regularly test yours with different lifts to see how you are progressing.

Why is the One Rep Max Calculation Useful?

Your one rep max calculation is useful because it gives you a record of your absolute strength at any point in time.

It provides accurate empirical data that can help you understand your progression in terms of strength.

Additionally, there will always be certain workouts, barbell complexes and training sessions that will require you to know your one rep maxes across different lifts.

How do you Find Out Your One Rep Max?

Standard procedure is to warm up first, then work up gradually in low volume sets and singles, adding more weight each time.

Once you reach the heaviest weight that you can manage then record the number. That is your one rep max lift.  

The standard measures for the one Rep Max are:

• Squat
• Bench Press
• Deadlift

However, you can also work them out for any other lift or exercise, depending on the information you need and your specific goals.

Turkish Get Up WODs

How to Calculate Your One-Rep Max

There is a selection of excellent calculators such as the one found on Strength Level.

Also, it can be useful to understand how the calculations work.

For this there are a multitude of different formulas that you can use to test your one rep max. Add your numbers (kg) into the equation and work out the answer.

• O’Conner formula: Weight × (1 + (0.025 × number of reps))
• Epley formula: Weight × (1 + (0.0333 × number of reps))
• Brzycki formula: Weight × (36 / (37 – number of reps))
• Lombardi formula: Weight × (number of reps ^ 0.1)

Training Tips

When it comes to finding out and measuring your one rep max, the following tips will help.

1. Don’t forget that each different exercise has its own respective one rep max. Your Deadlift 1RM will certainly be different to your Bench Press 1RM for example. Strength is specific for every exercise
2. The lower the number of repetitions that you enter into the calculator or formula, the more accurate the result will be. For example, knowing your 3RM will produce a more accurate representation of your 1RM than when you put in the numbers for your 20RM
3. When you are maxing out, don’t go past technical failure. If your form is breaking down then stop. No 1RM attempt is worth getting injured and losing six months of training over

How to Increase Your One Rep Max

Obviously increasing your actual strength and perfecting the technique for the respective lift are the main foundations of how to increase your one rep max.

However other factors come into play. For example, when you want to test a certain 1RM,

• Make sure that you are well rested and make the effort to give yourself the best possible chance of a good night’s sleep beforehand
• Ease into a long warm up
• Have a complete rest day prior to your lift attempts
• Plan your nutrition so that you will have energy and feel alert

When it comes to training, you can also try to peak for a 1RM attempt, like powerlifters would do for a meet.

Adjust the periodisation of your programming to include sets of 2 and 3 reps for a few weeks before you aim to test the 1RM.

Learn the Hindu Push Up

The following advice from Masterclass is a great way to program:

“Start at 70 percent: Start by lifting a weight that is 70 percent of your 1RM for 10–15 reps.

Increase to 80 percent: After becoming comfortable with the previous weight, increase the weight to 80 percent of your 1RM and practice lifting that amount for 5–10 reps. Practice with this weight for a few weeks.

Increase to 90 percent: When you’re ready, move up to 90 percent of 1RM for 3–4 sets of 3–4 reps and practice that for a few weeks.

Increase to 95 percent: Increase the weight to 95 percent of your 1RM for two sets of just 1–3 reps. This will be a challenging lift, so be sure to use a spotter to avoid an injury.

Increase to your 1RM: After you’ve become comfortable lifting 95 percent of your 1RM for multiple reps, try lifting your 1RM weight for more than one rep. At this point, you should be able to lift a slightly heavier weight for a maximum of one rep.

Use the help of a spotter or personal trainer to avoid injury when lifting your maximum weight.”

Repetition Percentages of 1RM

You can also see how you stack up against other lifters with this interesting calculator.