Deadlift max calculator

Deadlift: what the studies found

A study of seven formulas, as reported in source 2, found that every one of them underestimated the tested deadlift max, by 22.2 to 33.7 lb on average, or 9 to 14 percent. The predictions still tracked the tested maxes closely from person to person; they were all shifted down.

If that holds for you, a deadlift estimate here is more likely low than high. The spread between the six formulas does not show that gap, because all of them share it.

If you pull with a hex bar, the total weight is what the estimate uses. The drawing and the chart assume the bar weight you pick above the result.

How the estimate is worked out

The headline uses the Epley formula: estimated max = weight × (1 + reps ÷ 30). It is the formula the Masheen app uses for every set you log, so the estimate here and the estimate in the app come from the same sum.

The other five formulas run on the same weight and reps. At one rep this page returns the weight you lifted for every formula: you have shown you can lift it, and there is nothing to estimate.

Some tables print the Epley factor as 0.033 per rep, and the Brzycki formula as weight ÷ (1.0278 − 0.0278 × reps). Both are the same lines written another way.

When the estimate stops being trustworthy

A formula turns one set into a guess about a different effort. The further the set is from a single, the weaker the guess.

In a study of 70 adults aged 18 to 69, the closest predictions came from a five-rep set, and accuracy fell as the reps to failure went up. The authors conclude that no more than ten reps belong in the straight-line formulas, and every formula they compared did worse on ten-rep sets than on five-rep sets.

The spread on this page shows the same thing. At five reps the six formulas sit within about 6 percent of each other. At fifteen they are more than 20 percent apart. Past 12 reps the page marks the result as rough, as the app's own calculator does.

The set has to be a hard one. Every formula assumes the reps were close to the most you could do with that weight; an easy set gives a low number.

Bench press, squat and deadlift

The formulas are the same for every lift. How well they fit is not.

• Bench press max calculator. One study, as reported in a later paper, found two of seven formulas matched tested bench press maxes.
• Squat max calculator. One study, as reported in a later paper, found one of seven formulas matched tested squat maxes.
• Deadlift. One study, as reported in a later paper, found seven formulas all came out 9 to 14 percent under the tested deadlift max.
• One-rep max calculator.

Other lifts. The formulas take any weight and reps: incline or close-grip bench, rows, dumbbells, kettlebells. None of the six was built on those lifts in the sources we read, so read the number as a rough guide. For dumbbells, the result is a dumbbell number; nothing here converts it to a barbell lift.

How the chart rounds

Each row takes a percentage of the estimated max and moves it to the nearest weight you can build: the bar plus pairs of plates. With plates down to 1.25 kg that is a step of 2.5 kg; with plates down to 2.5 lb it is a step of 5 lb. When a figure falls exactly between two loads the chart takes the lower one, as the app does.

The "Exact" column shows the figure before rounding, so you can see how far each load moved.

The rep-max table turns the Epley formula round: max ÷ (1 + reps ÷ 30). It carries the same doubt as the estimate it starts from.

Sources

Read on 12 November 2026.

1. Reynolds JM, Gordon TJ, Robergs RA. Prediction of one repetition maximum strength from multiple repetition maximum testing and anthropometry. Journal of Strength and Conditioning Research, 2006; 20(3): 584–592. The published forms of the Brzycki, Epley, Lander, O'Connor, Lombardi and Mayhew formulas (its Table 5); the five-rep and ten-rep findings; the finding on body measurements.
2. Eston R, Evans HJL. The validity of submaximal ratings of perceived exertion to predict one repetition maximum. Journal of Sports Science and Medicine, 2009; 8: 567–573. Reports the results of LeSuer and others (1997) on seven formulas in the bench press, squat and deadlift. We could not open the 1997 paper itself.
3. One-repetition maximum. Wikipedia. The Epley formula written as weight × (1 + reps ÷ 30) and the Brzycki formula as weight × 36 ÷ (37 − reps).

The first publications of the six formulas, as listed in source 1 (we have not read these): Epley B, Poundage chart, Boyd Epley Workout, 1985. Brzycki M, Strength testing: predicting a one-rep max from reps to fatigue, Journal of Health, Physical Education, Recreation and Dance, 1993. Landers J, Maximum based on reps, NSCA Journal, 1985. Lombardi VP, Beginning Weight Training, 1989. Mayhew JL, Ball T, Arnold M, Bowen J, Journal of Applied Sport Science Research, 1992. O'Connor B, Simmons J, O'Shea P, Weight Training Today, 1989.