# One-Rep Max Calculator Estimate your one-rep max from a weight and reps — with a full percentage table for programming your training. Runs entirely in your browser. | % of 1RM | Weight | ~Reps | | --- | --- | --- | | 100% | 114.6 kg | 1 | | 95% | 108.9 kg | 2 | | 90% | 103.1 kg | 4 | | 85% | 97.4 kg | 6 | | 80% | 91.7 kg | 8 | | 75% | 85.9 kg | 10 | | 70% | 80.2 kg | 12 | | 65% | 74.5 kg | 16 | | 60% | 68.8 kg | 20 | ### How it works A one-rep max is estimated from a heavier-rep set using two well-known formulas: **Epley** (`w×(1+reps/30)`) and **Brzycki** (`w×36/(37−reps)`). The headline figure is their average. The table then applies standard training percentages of that 1RM, with the rep count each load typically allows — useful for planning working sets. Estimates get less accurate above ~10 reps. All local. --- *Source: [ocxly.com/one-rep-max-calculator.html](https://ocxly.com/one-rep-max-calculator.html) — OCXLY, free 100% client-side privacy-first tools. Free one-rep max (1RM) calculator using the Epley and Brzycki formulas, with a full training percentage table, entirely in your browser.*