Estimate your 1RM
in seconds.
Comparison
No equation knows your technique, the exercise or your individual profile. That is why we show both the selected result and the full range.
Weights indicatives
Calculated from the result of the primary formula.
| Percentage | Weightr | Suggested use |
|---|
Definition
The one-rep max, written as 1RM, is the maximum weight you can lift once in an exercise with correct technique. Here it is not measured directly: it is estimated from weight, repetitions and, when available, RIR.
The value is specific to the exercise and the moment. Sleep, technique, fatigue, equipment and familiarity with heavy weights can change the actual result.
PerformApp formula
Two sets of 5 repetitions do not describe the same effort if one ends at failure and the other leaves three repetitions in reserve. PerformApp uses potential repetitions — completed repetitions plus RIR — to estimate the one-rep max more realistically.
If you do not enter RIR, it is treated as zero: the calculation therefore assumes that the set reached failure.
FAQ
Use the same formula consistently over time and also look at the range. Changing equation at every workout makes comparisons less useful. PerformApp is preselected because it replicates the one-rep max calculation shown in the app statistics.
No. It is a mathematical prediction. Your actual one-rep max can only be verified with a specific test, which is not necessary to use this tool.
In general, a short set close to failure provides more relevant information than a long set. Above 10 repetitions, the formulas tend to diverge more.
Yes. The equations are proportional to the weight: select lb and the results, range and table will remain in the same unit.
RIR means “repetitions in reserve”: how many correct repetitions you believe you could still complete at the end of the set. Leave it at zero if the set reached failure or if you want to ignore it.
Your next PR starts here
Log sets, weights and RIR. Watch your progress take shape, workout after workout.
Take the result into PerformApp.
Free · iOS and Android · No card requiredNote: results are indicative estimates, not medical or training prescriptions. Do not attempt maximum weights unless you can assess the risks, technique and conditions. If in doubt, consult a qualified professional.
