Free tool
Turn a set you have already completed into an estimated one-rep max and a table of working weights by reps in reserve.
Every figure and rating this tool shows comes from one set of tested rules, the same ones used across the Hub and our AI tools, with the method and sources named on the page.
Advertising never decides what we write or recommend. If something is wrong, we correct it and record the change.
Short answer: Enter the weight, the reps you did and how many reps you had left. The calculator estimates your one rep max with the Epley equation, then lists working weights for other reps and RIR.
A set you have already done
Estimated one-repetition maximum
80 kg
80 kg
From 60 kg × 8 reps at 2 RIR (Epley)
| Reps | 0 RIR | 1 RIR | 2 RIR | 3 RIR |
|---|---|---|---|---|
| 3 | 72.7 kg | 70.6 kg | 68.6 kg | 66.7 kg |
| 5 | 68.6 kg | 66.7 kg | 64.9 kg | 63.2 kg |
| 8 | 63.2 kg | 61.5 kg | 60 kg | 58.5 kg |
| 10 | 60 kg | 58.5 kg | 57.1 kg | — |
| 12 | 57.1 kg | — | — | — |
| Set | Weight | Each side |
|---|---|---|
| 1 | 22.5 kg | 1 × 1.25 |
| 2 | 32.5 kg | 1 × 5 + 1 × 1.25 |
| 3 | 40 kg | 1 × 10 |
| 4 | 50 kg | 1 × 15 |
| Working | 60 kg | 1 × 20 |
Roughly 40, 55, 70 and 85 per cent of the working weight, for a few easy reps each, then the working set. A general guide, not a prescription — add or drop steps to suit the lift and how you feel.
Uses the Epley equation, counting reps in reserve as reps you could have done. It is only an estimate from a set you have already completed, not a test of your maximum; a dash means the combination is outside the range the equation is reliable over. Round to the nearest weight your equipment allows.
This calculator uses the Epley equation: estimated 1RM = weight × (1 + reps ÷ 30). Reps in reserve are counted as reps you could have done, so a set of 8 with 2 left counts as 10.
The table turns your estimated max into loads for different rep targets and reps in reserve, so you can pick a weight that leaves the effort you want.
Formulas lose accuracy on long sets, so reps plus reps in reserve must be 12 or fewer. Treat the result as an estimate from a completed set, not a test of your true max.
Free for coaches, gyms and writers. Paste this code into your page; it stays up to date automatically.
The Epley estimate is load × (1 + effective repetitions ÷ 30). Effective repetitions are completed reps plus reps in reserve: the extra reps you believe you could have completed with the same technique. A single rep with none in reserve is returned as the entered load. The working-weight table rearranges the same equation for each target.
A completed set of 100 kg for 8 reps with 2 reps in reserve gives 10 effective repetitions. The calculator returns an estimated one-rep max of 133.3 kg. This is a calculation example, not a recommendation to attempt that weight.
Repetitions plus reps in reserve must be 12 or fewer. An estimate is not a tested maximum: technique, fatigue and the accuracy of your RIR estimate affect it. Keep comparisons to the same exercise, equipment and range of motion, and round working weights to what you can load.
No. Enter a set you have already completed. The result estimates a maximum without requiring a maximal attempt.
That target's reps plus reps in reserve exceed the calculator's supported range. The tool leaves it blank rather than showing an unsupported estimate.
You believe you could have completed about two more full reps with the same technique. It is a subjective estimate, not a measured fact.
Share this calculator
Print it or save it to your phone. No email or sign-up. All templates
Free printable · 1 page · A4
The warm-up steps before your working weight, worked out for common weights with plates per side.
Share this template
Free printable · 1 page · A4
The effort scale on one card: what RPE 10, 9, 8 and 7 mean in reps left, plus a log to practise judging it.
Share this template
Free printable · 1 page · A4
Exactly which plates go on each side for every weight from 40 kg to 220 kg on a 20 kg bar.
Share this template
Educational information for adults aged 18 and over. It does not diagnose, treat or manage any medical condition. If you have a health condition, or symptoms that worry you, speak to your doctor or a health professional.