One Rep Max Calculator
Estimate your 1RM from any set and get a full percentage-based training table.
How this 1RM calculator works
Enter the weight you lifted and the number of reps you completed in a set (best used with sets of 1–10 reps). The calculator applies three formulas — Epley (1978), Brzycki (1993), and Lander (1985) — and displays all three results plus an average.
Using the progression table
The table shows percentage-based loads derived from your estimated 1RM. This is the foundation of percentage-based programming. If your squat 1RM is 140 kg, then 80% is 112 kg — the load you'd use for a set of 5 on a typical strength day.
Frequently Asked Questions
- Which formula is most accurate?
- Studies show no single formula is universally superior. Epley tends to overestimate for higher rep sets; Brzycki is more accurate up to ~10 reps. Using the average of all three gives a reliable estimate.
- Is it safe to test my actual 1RM?
- True 1RM testing carries injury risk, especially for beginners. The estimated 1RM from this calculator (based on a submaximal set) is safer for programming and nearly as accurate for most lifters.
- How do I use the training table?
- Choose a percentage based on your rep target for the day. Working at 80% for sets of 5–6 reps is a common strength training prescription. 60–65% is typical for hypertrophy work of 12–15 reps.
- How often should I re-test my 1RM?
- Most powerlifters estimate 1RM from a heavy set every 4–8 weeks (at the end of a training block). Daily 1RM testing is counterproductive — it generates fatigue without additional strength gains.