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One Rep Max Calculators Inaccurate

Anyone else find these to be very innacurate? I kind of use one to keep track of my rep progress on 531. But I know I could hit more than what it calculates on any given day. Do I just suck at reps? Not super important, just curious how accurate they are for others.

On squats I’m better at 1RM than reps. On bench and deadlift I’m better at reps than 1RM. OHP about the same.

Different for different individuals

See your doctor. The calculator cant be wrong so something is up with you.


Overhead is the only one that’s remotely close for me. Deadlift is the furthest from the mark.

You could just take your one rep max and multiply it by 1.


I’ve found this to be inaccurate as well.

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Must be. I figured as much. I consulted Dr. Google. He says I have testicular cancer.

Calculator is usually withing the 10lbs range of my actual lifts.

More seriously, I’ve only ever found these to be demotivating. I think you’re better off keeping rep records and using common sense. I mean, it is okay as a beginner but as you get more experienced your judgement should work better for you.

Josh Bryant recently did a relevant youtube video where he talks about guys whose 1RM strength is not carried over into rep work.


I think you’re onto the right approach. Maybe you need to guesstimate every now and then from maxes to reps or the other way for some reason but best way is to do it and know.

That being said plenty of top guys do the rep max / 1RM calculations and use them so it can’t be that bad

They are good for a rough estimate of your possible strength. They tend to be less accurate when you tabulate using higher reps.