How the calculation works
Enter the deadlift weight and completed repetitions. The calculator applies the selected named equation to estimate one-repetition maximum. Use a recent technically consistent set, preferably with fewer repetitions, and record stance, grip, belt, straps, bar height, and dead-stop or touch-and-go style.
- Epley estimate = weight × (1 + repetitions / 30).
- Brzycki estimate = weight × 36 / (37 − repetitions).
- If the tool averages equations, show every component estimate and state that the average is a site method rather than a published equation.
- Convert units once and retain full precision until the final display.
Continue with the One-Rep Max Calculator. Estimate 1RM from a technically consistent submaximal set.
Worked example
For 180 kg × 3, Epley gives 198.0 kg and Brzycki gives about 190.6 kg. A responsible result shows both or names the selected equation. It does not claim that the lifter can certainly pull the larger number on a specific day.
Continue with the Powerlifting Total Calculator. Add the best successful squat, bench, and deadlift.
How to interpret the result
- Prediction equations return different values because they model the relationship between load and repetitions differently.
- Deadlift estimates are sensitive to whether repetitions started from a dead stop or used rebound, and to whether grip or conditioning ended the set before the target muscles did.
- A tested competition result, a gym max, and an equation estimate are different records. Label them accordingly.
Limits and safety
- The calculator does not apply unsourced universal corrections for sumo versus conventional stance, belt use, grip, or touch-and-go repetitions.
- High-repetition sets add fatigue and technique variability.
- A calculator cannot assess readiness, pain, technique, or safe max-attempt conditions.
Frequently asked questions
Which deadlift 1RM equation is best
No equation is best for every lifter. Show the selected method and compare outputs when possible.
Can I use touch and go reps
You can, but label the estimate and avoid comparing it directly with a dead-stop estimate.
How many repetitions should I use
Lower-repetition technically consistent sets generally require less extrapolation than high-repetition sets.
Should I test the estimate
Only when appropriate for your experience, technique, health, and supervision. Most programming does not require frequent maximal tests.
Sources
- LeSuer et al 1997 study PDF — Comparison of repetition-based 1RM prediction equations.
- Prediction of one repetition maximum strength — A validation study in a defined group of trained male high-school athletes.
- ACSM Resistance Training Guidelines Update 2026 — Current overview of the 2026 resistance training position stand.