How strong you are, and how sure that is
Every app shows one estimated one-rep max. The five formulas behind it disagree by several per cent at five reps and wildly past ten, and the disagreement is the only thing that tells you how much to trust the number. This shows all of it, turns it into what to put on the bar, and tracks whether you are actually getting stronger.
This is arithmetic, not medical advice, and an estimated maximum is an estimate — never load a bar to a number a web page gave you without working up to it. Nothing you type is uploaded.
A set you actually did
Weight, and the reps you got. Taken close to failure, or the estimate means little.
The spread between them is the uncertainty. At three reps they agree within a couple of per cent; at twelve they are measuring how long you can keep going as much as how much you can lift, which is a different quality.
What to put on the bar
Every percentage, rounded to plates that exist.
Whether it is going up
Log the top set each session. The estimate is the thing to compare, not the weight — three at 100 beats five at 95.
Why five formulas instead of one
Epley, Brzycki, Lombardi, O'Conner and Wathan were each fitted to a different group of lifters doing a different lift, and they disagree in a way that grows with the rep count. At three reps they land within about two per cent of each other. At ten they can be five per cent apart, and at fifteen the question has changed: you are measuring muscular endurance, which correlates with maximal strength but is not the same thing. Showing one number hides all of that. Showing the range tells you whether to trust it to the kilo or to the five kilos.
Reps in reserve, and why it is asked
Every one of these formulas assumes the set was taken to the point where another rep was not happening. A set of five with three left in the tank is not a set of five for this purpose — it is closer to a set of eight. When you say how many you had left, the estimate is adjusted to the set you could have done, which is what the formulas were fitted on.
Tracking the estimate, not the weight
Sessions are not comparable by weight alone: three reps at 100 kg is a better performance than five at 95, and five at 95 is better than three at 95. The estimated maximum puts all of them on one axis, which is the only honest way to see a trend through a training block where the reps change. What matters is the slope over months, not the difference between Tuesday and Thursday — day-to-day, sleep and stress move a top set by more than a fortnight of training does.
Common questions
Should I test a true one-rep max?
Rarely, and never without experience of the lift and someone watching. A max attempt carries the most risk and tells you roughly what a set of three already tells you. Most training decisions only need an estimate that is consistent with itself over time.
Why does the loading table stop at plates?
Because a programme that tells you to lift 87.3 kg is telling you to do something the gym cannot do. Every row is rounded down to a weight the plates you selected can actually make, and the shortfall is shown so you know what was given up.
Is anything I log sent anywhere?
No. It is kept in this browser's own storage, and nothing leaves your device. There is no account.