How to Find Your Estimated 1 Rep Max

If you are new to resistance training, you may have begun to notice training programs or social media posts referring to a 1RM or 1 rep max. This is because the weight used for a particular number of repetitions is generally based off of your 1RM. There are a couple ways to find 1RM. You can just do set after set of an exercise, resting 3 minutes in between sets, until you can only do 1 rep of that exercise OR you can calculate your estimated 1RM.

Generally speaking, if I'm working with someone who is new to lifting, I opt for the estimated 1RM because that individual's body is not used to doing full-body exercises under intense load. Doing 1RM testing on this population will not only result in poor form, increasing risk of injury, but it may also yield an inaccurate representation of what the individual may be able to lift at higher rep schemes. Bonus! Finding the estimated 1RM also takes less time.

The first step is to pick a weight that you believe you can do for 5-10 repetitions, then perform the exercise doing as many reps as you can at that weight. Next, you need to find the percentage of 1RM that weight represents. Below is a chart that can be used as a reference.

Number of Repetitions	Percentage of 1 Rep Max
1	100%
2	95%
3	93%
4	90%
5	87%
6	85%
7	83%
8	80%
9	77%
10	75%

Let's say you performed 8 reps at your chosen weight. You performed 8 reps at 80% of your 1RM.

The last thing you need to is calculate your estimated 1RM. That part is easy. Divide the weight you used by the percentage. Let's say you did 8 squats at 100 pounds. The equation would look like this:

1RM = 100lbs/.8

1RM = 125lbs

Once you know your estimated 1RM, you can use it to plan out what weight to use for a specific rep scheme. Let's say you're performing squats for 3 sets of 10 repetitions. Multiply 75% by your 1RM to find the highest weight you can use for your squats. This will give you your 10 rep max.

10RM = 125 x .75

10RM = 93.75lbs

(or approximately 94lbs)

One more thing to note: When working at your repetition maximum, you are working at capacity. However, you can still gain strength at slightly lower intensities. Doing the squats at 85-95% of your repetition maximum will still yield results without stressing the body as much. Again, just multiply the repetition maximum by the percentage of the rep max you want to perform the squats at. Let's say you want to do 10 squats at 90% of your 10RM.

90% of 10RM = 94lbs x .9

90% of 10RM = 84.6lbs

(or approximately 85lbs)