Weight Training Load Calculator


Weight Lifted (lbs):

Number of reps completed:

Your estimated 1RM is lbs (+/- 5lbs)

Resistance training, or weight training, is an excellent way to improve muscular fitness and increase muscle mass and bone density. Aside from good form and technique, the key to proper weight training is to understand how much weight to lift to effectively stimulate the muscles while simultaneously avoiding injury.

A common training practice for experienced weight lifters and athletes is to lift weight loads that correspond to a percentage of their one repetition maximum, or 1RM. To do this, an athlete must first perform a 1RM test to determine the maximum amount of weight that they can lift just one time, usually while performing a leg press or bench press exercise. Lifting maximum weight loads is not recommended for most people because the risk of injury outweighs the benefit of doing so.

For safe and effective resistance training, the American College of Sports Medicine (2022) recommends that the average, healthy person perform at least one set of 8 to 12 repetitions (or lifts) of a weight that feels challenging by the last couple of repetitions. This method of training corresponds to a resistance that is approximately 60–70% of a person's 1RM and is a sound guideline that will improve muscular fitness. Following this type of program for all the major muscle groups, on at least 2 days per week (with at least one day of rest in between weight workouts) is appropriate for most exercisers.

What Does 1RM Mean to You?

If you have been consistently weight training for a while and are curious about your muscular strength potential, there is a way to determine your 1RM for certain exercises without actually having to perform a high-risk 1RM test. 1RM prediction coefficients have been developed for the leg press, squat, bench press, and chest press exercises. A prediction coefficient is a technical description for estimating your 1RM based on how much weight you can lift a certain number of repetitions. For example, if you can bench press 100 lb for 8 repetitions before becoming fatigued, your estimated 1RM is 125.5 lb.

This information may be useful if you are interested in tracking your progress in strength without actually having to perform a 1RM strength test. To figure out your estimated 1RM for the leg press, squat, bench press, and/or chest press exercises, input the heaviest amount of weight you have safely lifted for a specific exercise and the number of repetitions you completed at that weight.

American College of Sports Medicine (2022). ACSM's Guidelines for Exercise Testing and Prescription, 11th ed. Wolters Kluwer, Philadelphia, PA.