One Rep Max
Estimate 1RM from a submaximal set.
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Type the load and how many reps you completed. Formulas diverge after about 10 reps. Do not attempt a true max without training and spotting.
How to use this tool
- Enter your measurements. Use the units shown on the labels. Do not send medical data anywhere.
- Read the estimate. These formulas are public rules of thumb, not a diagnosis.
- Talk to a clinician for decisions. Do not change medicine, diet, or training from this page alone.
Safety
An estimated 1RM is not permission to load that weight. Injury risk is real. This is gym math, not a program.
Frequently asked
Which formula should I trust?
Compare two. If they disagree a lot, the set was probably too high-rep for a good estimate.
Does it work for kettlebells or machines?
The equations assume a simple barbell set. Machines change the leverage.
Can I get a percentages table?
Yes. Estimated loads for 50-95% are listed.
Is this coaching advice?
No.
Should beginners test a real 1RM?
Usually no. Use submaximal estimates and a coach if you have one.