One Rep Max Calculator
Estimate your one rep max from any rep set using the Epley formula, plus Brzycki and Lombardi as cross-checks. Includes a 50–90% training table.
Your set
Accuracy drops past 10 reps.
Training percentages
Based on your Epley 1RM. Use these to program working sets.
| % of 1RM | Weight | Typical reps |
|---|---|---|
| 90% | 105 kg | 2–4 |
| 80% | 93 kg | 6–8 |
| 70% | 82 kg | 10–12 |
| 60% | 70 kg | 12–15 |
| 50% | 58 kg | 15+ |
How to use your 1RM
A reliable 1RM is the backbone of most strength programs. Use the percentage table to choose working weights — heavy sets of 3–5 around 80–90%, hypertrophy work at 65–75%, and speed/quality sets at 50–65%.
Strength training disclaimer: Always warm up properly, use safe equipment and ask a spotter for help on heavy work. The estimate is a planning tool, not an instruction to attempt a maximal lift.
What your 1RM estimate means
Your estimated 1RM is the heaviest single rep you could probably lift, based on the reps and weight you entered. It's calculated from equations (Epley, Brzycki, Lombardi) that fit typical strength curves, and it's most accurate in the 3–8 rep range.
Use it to program percentages — 70% for volume work, 85%+ for heavy singles — rather than as a number to chase in the gym every week.
When to use the one rep max calculator
It's ideal when you're writing a training block and need working weights, or after a rep-out set to see roughly where your strength sits without actually testing a max.
Retest by plugging in a fresh rep-out every 4–6 weeks. Actual max testing is best saved for meets or programmed peaks.
Frequently asked questions
Which formula is most accurate?+
All three formulas (Epley, Brzycki, Lombardi) are accurate within ~5% for sets of 1–10 reps. We show all three plus an average so you can sanity-check.
How often should I test 1RM?+
Most lifters retest every 8–12 weeks. Day-to-day estimates from sets of 3–6 reps are usually enough for programming.
Why isn't my AMRAP set matching the table?+
Bar speed, technique and fatigue all influence rep counts. Use the table as a guide, not law.
Can I use this for any lift?+
Yes — it works for squat, bench, deadlift and most barbell lifts. Accuracy decreases beyond ~10 reps.
Health disclaimer: Caloritix provides estimate-based health and fitness calculators for general educational purposes only. Results are not medical advice and should not replace guidance from a qualified healthcare professional.