Deadlift 1RM Calculator
Estimate your deadlift max from a recent heavy set. Research suggests formula estimates tend to run low on this lift — here is what that means for your number.
Deadlift 1RM calculator
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Prefilled with the set you entered. Change the top set to plan a different session.
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How to estimate your deadlift max
Pull a weight you can lift for 2–5 clean reps, resetting each rep from the floor, and enter the weight and reps above. For example, 315 lb × 3 estimates a deadlift max of roughly 334–359 lb — though your true max may be higher, because formulas have been found to underestimate the deadlift.
Why deadlift estimates may read low
In a study that compared seven published 1RM equations against tested maxes in the bench press, squat and deadlift, every equation significantly underestimated the deadlift(LeSuer et al., 1997). The study tested untrained college students, so the size of the gap for experienced lifters is not known — but the direction is worth knowing.
A plausible explanation (our reasoning, not a finding of that study): on high-rep deadlift sets, grip and lower-back fatigue often end the set before the legs and hips are truly exhausted. A single does not suffer from that fatigue, so people can often lift more than a long set predicts. Lower-rep sets (2–5) reduce the problem.
Treat the deadlift estimate as a conservative guide. The top of the range, or a little above the Average Estimate, may be closer to your real max — but do not program from an optimistic number.
What counts as a clean deadlift rep
- Dead-stop reps give the most honest estimate. Bouncing the plates off the floor (touch-and-go) uses rebound and makes the set easier.
- Lockout counts: stand fully upright with hips and knees locked. No hitching the bar up the thighs.
- Use the same grip, stance (conventional or sumo) and equipment as the max you want to predict. Straps help grip on high-rep sets, so an estimate from strapped reps may not match an unstrapped max.
Deadlift safety for heavy sets
- Stop the set when your back position changes noticeably — a rep with poor position is not worth the estimate.
- Use plates of standard diameter so the bar starts at a consistent height.
- Leave a rep or two in reserve on high-rep sets; deadlift fatigue accumulates quickly.
Worked example
| Formula | Estimated 1RM |
|---|---|
| Epley | 346.5 lb |
| Brzycki | 333.5 lb |
| Lombardi | 351.6 lb |
| Mayhew | 359.1 lb |
| O'Conner | 338.6 lb |
| Wathan | 343.3 lb |
| Average Estimate | 345.4 lb |
The six formulas put this set between 333.5 and 359.1 lb— a 7.7% spread — with an Average Estimate of 345.4 lb.
Use the range, not just the middle number: plan training from the Average Estimate or lower, and treat the top of the range as optimistic.
Related tools and guides
- Squat Calculator
Estimate your squat max — and why depth changes the number.
- Plate Calculator
See which plates to load per side — never over your target.
- 1RM Formula Guide
All six equations compared rep by rep, and which to trust when.
- How to Test Your 1RM Safely
A step-by-step protocol for a true max — and when not to test.
Sources
- LeSuer, D. A., McCormick, J. H., Mayhew, J. L., Wasserstein, R. L., & Arnold, M. D. (1997). The accuracy of prediction equations for estimating 1-RM performance in the bench press, squat, and deadlift. Journal of Strength and Conditioning Research, 11(4), 211–213.
- Reynolds, J. M., Gordon, T. J., & Robergs, R. A. (2006). Prediction of one repetition maximum strength from multiple repetition maximum testing and anthropometry. Journal of Strength and Conditioning Research, 20(3), 584–592. Link (opens in a new tab)
- Human Performance Resources by CHAMP (HPRC), Uniformed Services University. What is a one-rep max? Link (opens in a new tab)