reckonerOne-rep max calculator
Estimate the most you could lift once from a set you already did. Tell it the weight, the reps and how many you had left, and it works the max back out along with the loads for every percentage you would train at.
1RM calculator
Give it a set you already did and how many reps you had left in the tank, and it estimates the most you could lift once. Reps in reserve are what make the estimate honest.
120 kg
100 kg for 5 reps with 1 left is 6 hard reps, about 83% of your max.
| What you are training | % of max | Load |
|---|---|---|
| Heavy single, RPE 9 | 95% | 115 kg |
| Triple | 92% | 110 kg |
| Five, top set | 87% | 105 kg |
| Eight, hypertrophy | 80% | 95 kg |
| Ten, back-off | 75% | 90 kg |
| Twelve, technique | 70% | 85 kg |
How to estimate a one-rep max without testing one
A one-rep max test costs you a session and tells you one number. An estimate costs you nothing, because you already did the work: a set of five with one rep left is six hard reps, and six hard reps at a given weight puts a fairly narrow bracket around what a single would be.
This uses the Epley formula with reps in reserve folded in, so the set you actually did is worth what it was actually worth. A set taken to failure and a set with three left are not the same set, and treating them the same is where most max estimates go wrong.
Treat the number as a working figure rather than a record. It is most accurate between three and eight hard reps, and it drifts once you get far above that, because high rep sets say more about your conditioning than about your top end.
Reckoner does this on every set, without being asked
You never open these. The plate loading appears under the target on the watch, and the max estimate updates itself after every set you log. Both know your bar and your plates already.