Lyfta Tools
1RM Calculator
Enter the weight you lifted and how many reps you hit to estimate your one rep max.
Your lift
Enter a set you could do with good form — a 2–10 rep set gives the most accurate estimate.
kg
reps
1RM = w × (1 + reps ÷ 30) — Widely used and robust across typical rep ranges. A solid default.
Estimated one rep max
116.5kg
Based on Epley (1985) — 100.0 kg × 5 reps
Training loads
Based on Epley| Reps | Weight (kg) | % of 1RM |
|---|---|---|
| 11RM | 116.5 | 100% |
| 2 | 109.5 | 94% |
| 3 | 106.0 | 91% |
| 4 | 103.0 | 88% |
| 5 | 100.0 | 86% |
| 6 | 97.0 | 83% |
| 8 | 92.0 | 79% |
| 10 | 87.5 | 75% |
| 12 | 83.5 | 71% |
These are estimates — actual performance varies with fatigue, technique, and exercise. Always use a spotter or safety equipment when testing near-maximal loads.
Track your real lifts with Lyfta
Log every set and let Lyfta track your estimated 1RM over time — across every exercise in your routine.
Frequently asked questions
- What is a one-rep max (1RM)?
- A one-rep max is the heaviest weight you can lift for a single clean repetition. Lifters use it to set training loads, track progress, and compare strength across sessions.
- Which 1RM formula is most accurate?
- Epley is a solid default for most gym sets. Brzycki is often more accurate at 10 reps or fewer. Wathan and Mayhew are well-supported in published research. Formulas agree closely for 2–5 reps and diverge at higher reps.
- How many reps should I use to estimate 1RM?
- A hard set of 2–10 reps with good form gives the most reliable estimate. Sets above 12 reps are less accurate because fatigue and conditioning start to matter more than max strength.
- Is an estimated 1RM the same as a tested max?
- No. An estimated 1RM is a prediction from a submaximal set. Actual maxes vary with sleep, technique, and fatigue. Use a spotter or safety equipment if you test a true one-rep max.