Calculating 1 Rep Max

Hey guys,

Can anyone direct me towards the preferred formula for calculating 1RM? I did some quick research on the Web and came back with 3 formulas: Brzycki, Epley, and Lander (each with varying coefficients). Does this cover the field or are there any other formulas worth looking at? And finally, which of these is the most popular/recommended? Thanks!

Dennis Weis did an article on this topic at then end of 2001, which would be a good reference to at least compare the formulas.

This may sounds asinine, but the only way to accurately assess your 1rm for any given lift is to “max” that particular lift. Regardless of which formula you use, there will be a margin of error. I even know people who brag about max lifts based on a formula. (IE: I can bench xxx ten times, so i should be able to max XXX. When in reality they couldn’t handle a bar loaded within 50lbs of what the formula says.)

The powerlifters that I used to work out with always said that if you add 11% to your 3RM you can get a good 1RM estimate. I’ve found that to be fairly accurate throughout my training career.

if you care what your max is, do a max. formulas are useless.

Point taken on the fact that actually performing a 1RM will (naturally) be more accurate than a calculation…However, to elaborate…many workout routines are based on lifting at a certain Intensity (%1RM). If a routine calls for doing a set at 60% intensity, then it seems to me I need to figure my 1RM and multiply it by 0.60 to determine the amount of weight I need to lift. Hence the need for a formula, as I don’t normally perform 1RM’s all the time for every little exercise. However, if anyone has an alternate approach, I am all ears.

I rather caluate a 1 RM by doing the 1 RM, its the most acurate, then I use the NSCA chart to find out what my 10RM would ect, and so forth. I feel its more of an acurate test.

some people don’t want the risk of doing one rep maxes. for those people, use the calculations you have. They are all estimates so use them as a reference point. And remember we are not talking about contest one rep maxes. just regular gym one rep maxes. the psychology of a contest is much different then it is during a training session. That’s why most people would not attempt to break a record in the gym if they are actually competing. they would much rather wait till the actual competition to peak. laters pk

I think that part of the fact that a formula such as (1 RM = 3 RM plus 11%) may work well for many powerlifters, is that if you don’t have that kind of increase from 3RM to 1RM, then you won’t be a decent powerlifter and won’t be trying the formula! For the general population, it will fail for many.

While agreeing with the principle that learning to do maximum singles and building that skill is the only way to arrive at a true 1RM value, a good result for I think practically anyone is obtained by estimating 1RM as equal to 3RM plus the difference between 3RM and 6RM. When the gap between 3RM and 6RM is small, rather consistently the gap between 3RM and 1RM is similarly small also: likewise where the gap of one is large, it rather consistently is large for the other as well. The exception may be if Golgi tendon inhibition limits the 1RM performance. If so, though, in terms of planning training cycles the calculated value, representing an estimate of potential strength ignoring that limitation, probably is a more useful value than the actual one, I would think.

I have always used the chart on the “Critical Bench” website. These numbers work very well for me and other lifters I know for calculating 1RM. The site claims to calculate it well for all lifts, but I don’t trust it as much for the squat and deadlift as opposed to the bench which there site is about. Of course, if you are better at handling heavy weights your max may exceed and if not it will fall below the prediction. Luke Mueller would always repa little more than me, but my bench max has always been 10-20 pounds more.