one-rep max calculator
Estimate a one-rep max from any weight and reps, with the same three formulas the platform prescribes from. Every result carries the estimated mark, because an estimate is never a measured max.
Whole reps, taken close to failure. Five to eight give the steadiest read.
Most lifts. An Epley-family curve tuned to the platform's logged data, slightly more conservative than the textbook.
Every figure above carries the estimated mark for a reason: a formula reads a set, it does not watch you lift. The platform treats its own numbers the same way, so an estimated max never poses as a measured one.
one curve does not fit every movement.
A bench press and a lat pulldown do not fatigue the same way, so the same set of eight reps implies a different max for each. In Trainbase, every exercise a coach adds carries the estimation curve it is measured by, and this calculator carries the same three.
- built for
- standardmost barbell and dumbbell lifts
- back and bicepsrows, pulldowns, curls
- leg press / extensionsmachine leg work
- shape
- standardEpley-family curve
- back and bicepsEpley-family, flatter
- leg press / extensionspower curve, deliberately flat
- character
- standardthe workhorse, tuned slightly conservative of the textbook
- back and bicepsthe most conservative, because pulls flatter a rep count
- leg press / extensionskeeps a twenty-rep leg press from fabricating a monster max
- confidence
- standardmedium-high, fit to logged training data
- back and bicepsthe lowest of the three; hold it loosely
- leg press / extensionshigh, fit to a clean measured grid
| standard | back and biceps | leg press / extensions | |
|---|---|---|---|
| built for | most barbell and dumbbell lifts | rows, pulldowns, curls | machine leg work |
| shape | Epley-family curve | Epley-family, flatter | power curve, deliberately flat |
| character | the workhorse, tuned slightly conservative of the textbook | the most conservative, because pulls flatter a rep count | keeps a twenty-rep leg press from fabricating a monster max |
| confidence | medium-high, fit to logged training data | the lowest of the three; hold it loosely | high, fit to a clean measured grid |
The same formulas resolve every percentage prescription inside the product. Read more about how that works on the one-rep max page.
the honest answers.
How accurate is an estimated one-rep max?
Accurate enough to program from, not accurate enough to call a record. Low-rep sets taken close to failure estimate tightest; past ten reps the relationship loosens, and past thirty we do not print a number at all. That is why every result here carries the estimated mark.
Why three formulas instead of one?
Because one curve does not hold every movement. Pulling movements overstate a max on the standard curve, and machine leg work overstates it even more, so every exercise a coach adds to Trainbase carries the curve it is measured by. This calculator gives you the same three.
What do I do with the percentages table?
That is how strength programs are written: a set prescribed at 75 percent of your one-rep max resolves to a concrete weight. On the platform that resolution happens automatically against each client's own numbers; here you can read it straight off the table.
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a calculator estimates once. the platform watches what actually happens.
Every number this page gives you is a starting point. Trainbase is where a coach and a client watch the real ones move: every set logged against a program, every reading on one honest scale, every estimate marked as an estimate. When the trend disagrees with the calculator, the trend wins.