Deadlift 1RM from 20 Reps — Epley and Brzycki Estimate
If you can deadlift 140 kg for 20 reps, your estimated one-rep max is 264.9 kg — the average of the Epley estimate (233.3 kg) and the Brzycki estimate (296.5 kg). That is the headline number, and the rest of this page shows exactly how it was calculated, what loads to train with at every percentage of it, and how far you should trust it.
The Deadlift works the hamstrings, glutes and back, and it is a barbell lift. An intermediate lifter often deadlifts around twice bodyweight, so a 140 kg deadlift for an 80 kg lifter is a respectable intermediate number. The worked example below uses a 20-rep set with 140 kg as the load — that is an assumption for illustration, not a prescription for you. Put your own weight and reps into the One Rep Max Calculator and the same two formulas will estimate your own max in seconds.
An estimated one-rep max matters because almost every serious strength programme is written in percentages of it. "Five sets of five at 80%" only means something if you know what 100% is, and testing a true one-rep max is risky, fatiguing and unnecessary for most lifters. A submaximal set of 20 reps gives you the number without the risk — provided you understand the limits of the formulas, which this page sets out honestly.
Use the one-rep-max calculator for your own numbers
The worked example on this page uses 140 kg for 20 reps. Your numbers will be different, and the calculator does the same maths with them. Use the Deadlift 1RM Calculator for this lift, or the general One Rep Max Calculator for any lift, and you will get the Epley estimate, the Brzycki estimate, their average, and the full training-percentage table for your own max.
For comparison, here are the other one-rep-max pages for the deadlift — the same two formulas applied to different rep counts:
- Deadlift 1RM from 15 Reps — Epley and Brzycki Estimate
- Deadlift 1RM from 12 Reps — Epley and Brzycki Estimate
- Deadlift 1RM from 3 Reps — Epley and Brzycki Estimate
The formulas, shown and cited
Two published formulas estimate a one-rep max from a submaximal set. Both are shown here with their sources, and both are worked through with this page's numbers.
Epley (Epley 1985): 1RM = weight × (1 + reps ÷ 30)
Brzycki (Brzycki 1993): 1RM = weight × 36 ÷ (37 − reps)
Worked through for 140 kg × 20 reps on the deadlift:
- Epley: 140 × (1 + 20 ÷ 30) = 140 × 1.7 = 233.3 kg
- Brzycki: 140 × 36 ÷ (37 − 20) = 140 × 36 ÷ 17 = 296.5 kg
- Average of the two: (233.3 + 296.5) ÷ 2 = 264.9 kg (584 lb)
The two formulas differ by 63.1 kg on this set. At 20 reps the formulas are outside their comfort zone, and you can see it in the gap: they differ by 23.8 percent here. A 20-rep set is an endurance test as much as a strength test — breathing, conditioning and mental toughness matter as much as maximal strength, and the formulas cannot separate those. Treat the average as a rough guide only, not a number to plan a strength block around. If you want a tighter estimate, re-test with a set of 5 to 8 reps; the 20-rep figure is most useful for setting endurance loads and for tracking whether your high-rep strength is improving over time.
Neither formula is magic. Both were fitted to real lifting data, and both assume the set was taken close to failure with good technique — a set of 20 reps with two more reps left in the tank will underestimate your max, because the formulas assume those 20 reps were hard. If you stopped well short of failure, add that to your interpretation: the estimate is a floor, not a ceiling. And if your technique broke down on the last rep, the set does not count for estimation purposes at all.
Training percentages for a 264.9 kg deadlift max
Most programmes prescribe loads as a percentage of your one-rep max. The table below gives the load for every percentage from 50% to 100% of the 264.9 kg estimate, so you can read your working weights straight off it without doing the multiplication in your head between sets.
| % of 1RM | Load (kg) | Load (lb) |
|---|---|---|
| 50% | 132.5 kg | 292 lb |
| 55% | 145.7 kg | 321 lb |
| 60% | 158.9 kg | 350 lb |
| 65% | 172.2 kg | 380 lb |
| 70% | 185.4 kg | 409 lb |
| 75% | 198.7 kg | 438 lb |
| 80% | 211.9 kg | 467 lb |
| 85% | 225.2 kg | 496 lb |
| 90% | 238.4 kg | 526 lb |
| 95% | 251.7 kg | 555 lb |
| 100% | 264.9 kg | 584 lb |
How those percentages are used in practice depends on the goal. Strength work lives at 85–95% of 1RM for sets of 1–5 reps, with long rests of three to five minutes. Hypertrophy work lives at 65–85% for sets of 6–12 reps, with rests of 60–120 seconds. Muscular endurance work lives at 50–65% for sets of 15 or more reps, with short rests. The same max produces all three training zones; what changes is the percentage and the rep count, not the lift.
A practical example: if your programme calls for five sets of five at 80% on the deadlift, that is 211.9 kg for five reps, five times, with three minutes of rest between sets. If it calls for three sets of ten at 70%, that is 185.4 kg for ten reps, three times, with 90 seconds of rest. The table above is the only arithmetic you need; the programme supplies the sets, reps and rest.
What you can lift for other rep counts
If your estimated max is 264.9 kg, the table below gives the load you should be able to handle for each rep count, worked out from the Epley relationship between reps and percentage of maximum. Use it to pick weights for any set in your programme, not just the ones at your tested rep count.
| Reps | Estimated load (kg) | Estimated load (lb) |
|---|---|---|
| 1 | 256.4 kg | 565 lb |
| 2 | 248.3 kg | 548 lb |
| 3 | 240.8 kg | 531 lb |
| 5 | 227.1 kg | 501 lb |
| 6 | 220.8 kg | 487 lb |
| 8 | 209.1 kg | 461 lb |
| 10 | 198.7 kg | 438 lb |
| 12 | 189.2 kg | 417 lb |
| 15 | 176.6 kg | 389 lb |
| 20 | 158.9 kg | 350 lb |
The row for 20 reps reads 158.9 kg, which sits within a kilogram or two of the 140 kg used in the worked example — the small difference is because this table is built from the averaged estimate rather than from either formula alone. That is the honest way to read it: the table is a guide for choosing weights, and the right weight on the day is the one you can lift with good technique for the prescribed reps, not the number in the cell.
How to use the result, and how to progress safely
Use the 264.9 kg figure as a planning number, not as a weight to attempt tomorrow. The safest way to use an estimated max is to base your training percentages on it for four to six weeks, then re-test with a fresh submaximal set and update the estimate. If the new set gives a higher estimate, your training weights go up; if it gives the same number, you have maintained; if it gives a lower number, you may be under-recovered and need a lighter week.
Add 2.5 to 5 kg to the bar when you complete all prescribed sets and reps at a given weight. Train the deadlift once or twice a week, and keep the volume modest — heavy deadlift sets are the most fatiguing sets in the gym, and more deadlift volume is rarely the answer when progress stalls.
Warm up properly before any heavy set. For a deadlift session, that means a few light Romanian deadlifts or kettlebell hinges, then 50 percent of your working weight for a few reps, then 70 percent, then your working sets — never jumping straight from the warm-up to a heavy load. And never test a true one-rep max alone, without spotters or safety bars. The whole point of estimating from a 20-rep set is that you never have to find out what your true max is by attempting it.
Recovery is part of the programme, not a break from it. The deadlift stresses the hamstrings, glutes and back, and those muscles need 48–72 hours before they are trained hard again. Sleep, food and rest days are where the strength is actually built; the training session is just the stimulus. A lifter who adds weight to the bar every week while sleeping five hours a night will stall and then regress, and no formula can fix that.
Technique standards for the deadlift
The deadlift starts with the bar over the middle of the foot, shins touching the bar, hips back, chest up and lats tight, then the floor is pushed away while the bar stays close to the shins and thighs. The standard that matters most for estimation is the dead stop: each rep should start from a full stop on the floor, not bounced or touch-and-go. Touch-and-go reps use the bounce off the floor and will inflate the rep count, sometimes by two or three reps, which inflates the estimated max with it. A set only counts if every rep is reset on the floor with a flat back.
The most common errors are rounding the lower back, letting the hips shoot up before the chest, letting the bar drift away from the shins, and hitching the bar up the thighs. Each of these changes the lift into something easier or more dangerous, and none of them should count toward an estimate.
What the number does NOT tell you
An estimated one-rep max is a useful number with clear limits. First, it is an estimate, not a measurement. Your true max can only be found by attempting a maximum lift, and the estimate can be off by 5–10% in either direction even from a good set. That is why the percentage table above should be treated as a guide: if 80% feels like 90% on the day, trust the feeling, not the table.
Second, the formulas assume good technique. A deadlift performed with a shortened range of motion or momentum will produce a higher rep count than a strict set, and the formulas will reward that with an inflated max. Compare estimates only between sets done the same way — same depth, same pause, same standard. A stricter set that gives a lower estimate is more useful than a sloppy set that gives a higher one.
Third, a one-rep max says nothing about your health, your body composition or your overall fitness. It measures one thing — the most weight you can lift once in this movement — and a big number in one lift does not imply a big number in another, let alone general health. It also says nothing about injury risk: a lifter with a large estimated max and poor technique is closer to an injury than a lifter with a modest max and excellent technique.
Finally, the formulas are population tools. They were fitted to groups of lifters, and individuals vary. Some lifters are naturally better at high reps than at singles, and the formulas will underestimate their max; others are the opposite, and the formulas will overestimate. Over time you will learn your own pattern — whether your true max tends to sit above or below the estimate — and you can adjust your training percentages accordingly.
Frequently asked questions
What is my deadlift 1RM if I lift 140 kg for 20 reps?
Using the worked example on this page: Epley gives 233.3 kg and Brzycki gives 296.5 kg, so the averaged estimate is 264.9 kg. That figure assumes the 20-rep set was taken close to failure with good technique. For your own weight and rep count, use the Deadlift 1RM Calculator.
Which formula is better, Epley or Brzycki?
Neither is clearly better in general — that is why this page averages them. Epley (1985) tends to give slightly higher estimates at higher rep counts, while Brzycki (1993) is often a little more conservative. From sets of ten reps or fewer the two usually agree within a few kilograms, and the average is a sensible compromise. Above ten reps both become less reliable, and the gap between them — 63.1 kg here — is a warning sign rather than a detail to average away.
Why is a 1RM estimated from 20 reps less reliable?
Because both formulas were fitted to low-rep data, and at 20 reps the set tests endurance and conditioning as much as maximal strength. Epley and Brzycki diverge sharply at high reps, so their average is a rough guide rather than a precise number. Use it to set endurance loads and to track high-rep progress, and re-test at 10 reps or fewer when you need a number to plan heavy training around.
Does touch-and-go change my deadlift estimate?
Yes, and usually by a lot. Touch-and-go reps bounce off the floor and can add two or three reps to a set, which inflates the estimated max. For an honest estimate, reset every rep from a dead stop on the floor, with a flat back and the bar over the mid-foot.
What weight should I train with for strength on the deadlift?
Strength work is usually 85–95% of your estimated max. For a 264.9 kg max, that is 225.2 kg to 251.7 kg, for sets of 1–5 reps with three to five minutes of rest. For muscle growth, use 65–85% (172.2–225.2 kg) for sets of 6–12 reps. The full percentage table above covers every step from 50% to 100%.
How often should I re-test my deadlift max?
Every four to eight weeks is enough for most lifters. Testing more often wastes training time and adds fatigue without new information, because strength changes slowly. Re-test with the same rep count and the same technique standard as last time, so the two estimates are genuinely comparable, and update your training percentages from the new figure.
Related pages
Estimates only, not medical advice. Minimum safe intakes: 1,200 kcal/day women, 1,500 kcal/day men — consult a healthcare professional before a very-low-calorie diet.