How accurate is Brzycki?
Within 2-5 lbs in 3-5 rep range. Accuracy decreases above 10 reps.
Health Fitness
Deadlift 1RM Calculator
Calculate deadlift 1rm with your details.
Personalized estimate
Use realistic inputs for the most useful results.
What this calculator does
Deadlift 1RM calculator estimates maximum lift from submaximal sets using Brzycki formula. Safer than testing actual max while providing data for programming.
How it works
Brzycki uses weight lifted and reps completed. Most accurate with 3-8 reps.
Formula
1RM = Weight ÷ [1.0278 - (0.0278 × Reps)]. 300 lbs × 5 reps ≈ 337 lbs 1RM.
Tips for using this calculator
- Use 3-8 rep sets for accuracy
- Test when fresh and rested
- Add 5-10 lbs safety margin when training at percentages
- Use estimated 1RM for programming, not actual max attempts
- Retest every 4-8 weeks
Frequently asked questions
Should I use this to attempt actual 1RM?
Use it for programming. If testing actual max, start 5-10 lbs lighter with proper warm-up and spotters.
Does this work for all lifts?
Yes, Brzycki works for all major barbell and dumbbell exercises.