🏋️ 1RM & Running Pace Calculator
Estimate your one-rep max (1RM) from a set you actually did, and convert between running pace, distance, and finish time. Two tools for the two halves of training.
Most accurate at 1–10 reps.
Estimated 1RM
115 kg
Average of Epley & Brzycki
Training percentages
| % of 1RM | Weight | ≈ reps |
|---|---|---|
| 100% | 115 kg | 1 |
| 95% | 109 kg | 2 |
| 90% | 103 kg | 4 |
| 85% | 97 kg | 6 |
| 80% | 92 kg | 8 |
| 75% | 86 kg | 10 |
| 70% | 80 kg | 12 |
| 65% | 74 kg | 15 |
| 60% | 69 kg | 20 |
Why estimate a 1RM
Testing a true one-rep max is risky and fatiguing, so coaches estimate it from a lighter set using formulas like Epley and Brzycki. The estimate is most accurate at 1–10 reps and drifts as reps climb. Use your estimated 1RM to set working weights — e.g. ~70% for hypertrophy, 85%+ for strength.
These calculators give population-level estimates for healthy adults and are not medical advice. If you are pregnant, under 18, or managing a health condition, talk to a professional.