Key Takeaways
- Your 10RM is the heaviest weight you can lift for 10 reps. This calculator estimates it from a hard set of 2 to 10 reps or from a 1RM, using seven published equations[2]. If you enter a real set of 10 to failure, the 10RM is the weight you lifted and the page estimates your 1RM instead.
- Ten reps is not a fixed 75% of your 1RM. The seven equations put it at 74.2% to 80%[2], and in 90 adults the measured 10RM averaged 75.65% of the 1RM on the bench press and 70.1% on the leg press[3].
- Ten reps is the edge of what these equations were built for. In the same study a 5RM predicted the 1RM better than a 10RM[3], so a heavier set of 4 to 6 reps gives a firmer 1RM if you have one.
- Treat the result as an estimate. The Australian Institute of Sport testing manual puts the variability of submaximal predictions at about 10%[11], and in one study all seven equations came out low for the deadlift[2].
- I couldn't source strength standards, a 10RM-based training plan or fat-loss claims, so they aren't here. The last section lists what was removed from the old version of this page.
What a 10RM Is, and What It Is Not
A 10 rep max (10RM) is the heaviest weight you can lift for 10 reps in one set, with form you would accept in training. If an eleventh rep is possible, the weight was below your 10RM.
The term comes from 1940s rehabilitation work by Thomas DeLorme[8]. A 2003 trial paper describes his 10RM as the weight a person can lift only ten times before the muscle temporarily fails[7].
I read only the abstract of DeLorme's 1945 paper. The definition above comes from the 2003 paper, so treat it as second-hand.
How the Estimate Works
Each of these equations was written to turn a set taken to fatigue into a 1RM. The calculator runs it forward to get a 1RM, then backward to get the load for 10 reps.
What happens when you press Calculate
- Each equation turns your weight and reps into a 1RM estimate.
- The same equation then divides that 1RM by its own 10-rep factor to get a 10RM.
- The page shows the lowest, highest and average of the seven answers.
- For bench press and leg press, it adds the average 10RM measured in a real study[3].
With a set of exactly 10 to failure, the two steps cancel and you get your own weight back as the 10RM. The page then estimates your 1RM instead.
LeSuer and colleagues print the seven equations in their Table 1[2]. Here they are, with the share of 1RM each gives for 10 reps and the 1RM that follows from a 10RM of 100:
| Equation | Form | 10 reps as % of 1RM | 1RM from a 10RM of 100 | Original publication |
|---|---|---|---|---|
| Epley | 1RM = w × (1 + 0.0333 × r) | 75% | 133.3 | Epley, Poundage Chart, 1985 (not opened) |
| Brzycki | 1RM = 100 × w ÷ (102.78 − 2.78 × r) | 75% | 133.4 | Brzycki, 1993 (opened and checked) |
| Lander | 1RM = 100 × w ÷ (101.3 − 2.67123 × r) | 74.6% | 134.1 | Lander, NSCA Journal, 1985 (not opened) |
| Lombardi | 1RM = w × r^0.1 | 79.4% | 125.9 | Lombardi, Beginning Weight Training, 1989 (not opened) |
| Mayhew | 1RM = 100 × w ÷ (52.2 + 41.9 × e^(−0.055 × r)) | 76.4% | 130.9 | Mayhew et al., J Appl Sport Sci Res, 1992 (not opened) |
| O'Conner | 1RM = w × (1 + 0.025 × r) | 80% | 125 | O'Conner et al., Weight Training Today, 1989 (not opened) |
| Wathan | 1RM = 100 × w ÷ (48.8 + 53.8 × e^(−0.075 × r)) | 74.2% | 134.7 | Wathan, in Baechle (ed.), 1994 (not opened) |
w is the weight lifted and r is the reps to fatigue. The last two columns are arithmetic on each equation at 10 reps.
Brzycki's paper has its own table for this equation. A 225 lb set of 10 predicts a 1RM of about 300 lb, and a 200 lb 1RM comes down to about 150 lb for 10 reps[1]. The calculator reproduces those values in its tests.
Brzycki didn't fit his equation to lifters he tested. He anchored it on an unpublished observation, passed on through a 1981 review, that about 10 reps can be done at roughly 75% of a max[1].
I opened only Brzycki's paper. The other six equations come from LeSuer's table, and I didn't open their original publications, so I can't say how they were derived.
Worked example: 100 kg for 5 reps to failure
Brzycki 1RM = 100 × 100 ÷ (102.78 − 2.78 × 5) = 112.5 kg
Brzycki 10RM = 112.5 ÷ (100 ÷ (102.78 − 2.78 × 10)) = 84.4 kg
Epley 1RM = 100 × (1 + 0.0333 × 5) = 116.7 kg
Epley 10RM = 116.7 ÷ (1 + 0.0333 × 10) = 87.5 kg
The average is there because most people want one number. The studies I read don't name a best equation, and I found no test of the average itself, so lean on the range.
Converting a 10RM to a 1RM, and Back
Enter a set of 10 reps to failure and the page gives the 1RM. Multiply the 10RM by the factor for any equation to do it by hand: 1.25 to 1.35, depending on which one you pick.
| 10RM (kg) | Average 1RM (kg) | Range (kg) |
|---|---|---|
| 40 | 52.4 | 50 to 53.9 |
| 60 | 78.6 | 75 to 80.8 |
| 80 | 104.8 | 100 to 107.8 |
| 100 | 131 | 125 to 134.7 |
| 120 | 157.3 | 150 to 161.7 |
| 140 | 183.5 | 175 to 188.6 |
1RM estimated from a 10RM to failure, in kg. Average and range of the seven equations.
For the reverse, switch to "I know my 1RM". That direction is arithmetic on the same equations, and I found no study that tested it, so it's the less certain of the two.
| 1RM (kg) | Average 10RM (kg) | Range (kg) |
|---|---|---|
| 60 | 45.8 | 44.5 to 48 |
| 80 | 61.1 | 59.4 to 64 |
| 100 | 76.4 | 74.2 to 80 |
| 120 | 91.6 | 89.1 to 96 |
| 140 | 106.9 | 103.9 to 112 |
| 160 | 122.2 | 118.7 to 128 |
10RM estimated from a 1RM, in kg. Average and range of the seven equations.
Measured data covers the forward direction for one lift. Reynolds and colleagues fitted a line through real 10RM and 1RM results on the leg press, with reps paced to a metronome at 30 a minute[3]:
| Lift | 1RM from 10RM | Standard error | R² |
|---|---|---|---|
| Plate-loaded leg press | 1.2091 × 10RM + 38.0908 | 26.13 kg | 0.933 |
Reynolds et al. (2006). 70 adults aged 18 to 69. Weights in kg.
The calculator shows this line only for a real leg press set of 10 to failure. The bench press equation in the same paper needs your fat-free mass as a second input (R² 0.976, standard error 5.38 kg), so it isn't used here.
10RM as a Percentage of 1RM
Many calculators use one flat figure, 75%, for a 10RM. The seven equations give 74.2% to 80% at 10 reps[2], and Brzycki's equation was anchored on that 75% in the first place[1]. So it landing on 75% is by construction, not a test of the rule.
Measured data is the better test. Reynolds and colleagues recorded a real 10RM and 1RM in 90 adults, and the average share depended on the lift[3]:
| Source | 10 reps as % of 1RM |
|---|---|
| Measured, flat barbell bench press | 75.65% |
| Measured, plate-loaded leg press | 70.1% |
| The seven equations (arithmetic, see the table above) | 74.2% to 80% |
Mean 10RM as a percent of 1RM, Reynolds et al. (2006), combined groups, n = 90. I could not find the spread of these percentages in the paper's text.
The chest press average sits close to 75%, but the leg press average is about five points lower. The paper's own worked example gives 212 kg for 10 reps from a 300 kg leg press 1RM, and 113 kg from a 150 kg chest press 1RM[3].
Those come from nonlinear equations in the paper that I could not read, so the page does not use them.
I found no measured 10RM percentage for the squat, deadlift or other lifts, so the page shows none for them.
Brzycki himself noted that some people get fewer or more than 10 reps at 75% of their max. He suggested checking your own ratio by taking 75% of a tested 1RM and doing as many reps as you can[1].
How Accurate Is It?
This is what each source looked at, so you can judge how far to trust a number:
| Source | What it found | Limit |
|---|---|---|
| LeSuer et al., 1997[2] | 67 untrained college students (40 men, 27 women; some skipped the squat and deadlift) did a 1RM and a set of 10 or fewer reps to fatigue. All seven equations correlated highly with the measured 1RM (r above 0.95). Bench press: only Mayhew and Wathan did not differ significantly from the measured 1RM, and the other five came out 0.8 to 6% low on average. Squat: only Wathan did not differ, and the others were 2 to 8% low. Deadlift: all seven were low, by 9 to 14%. | Untrained students. Predicted a 1RM, not a 10RM. |
| Reynolds et al., 2006[3] | 70 people aged 18 to 69 did 1, 5, 10 and 20RM tests on the barbell bench press and a plate-loaded leg press. R² for predicting the 1RM: 5RM 0.993 bench and 0.974 leg press; 10RM 0.976 and 0.933; 20RM 0.955 and 0.915. The authors advise no more than 10 reps in linear equations, and report that every equation they compared was less accurate with the 10RM than the 5RM. | Bench press and leg press only. 10RM to 1RM, not the reverse. Reps were metronome-paced. |
| Dohoney et al., 2002[4] | 34 healthy men aged 19 to 32 did 1RM, 4 to 6RM and 7 to 10RM tests on five exercises. The 4 to 6RM equations predicted the 1RM more accurately than the 7 to 10RM ones. I also cite its soreness figures in the testing section below. | Men only, untrained, a 7 to 10RM range and not 10RM alone. I didn't use its equations because I couldn't confirm their units. |
| Mayhew et al., 2008[5] | 103 young women did bench press tests before and after 12 weeks of training. Prediction equations were more accurate when fewer than 10 reps to fatigue were used. | Young women, bench press only. |
| Australian Institute of Sport, 2022[11] | Its testing manual says prediction equations are influenced by the muscle group, the exercise and training level, with large variability (about 10%) when submaximal reps predict a maximum. When recording test results, it says to log the weight and reps actually lifted and not to use predictive equations to calculate a 1RM. | A testing manual that cites earlier studies, not a new experiment. Written for formal athlete testing. |
- Ten reps is the ceiling. Brzycki says his equation is only valid below 10 reps to fatigue[1]. LeSuer describes the equations as built on 10 or fewer[2], Reynolds advises no more than 10[3], and Mayhew found better accuracy below 10[5]. So the calculator accepts 2 to 10 reps, warns at 8 or more, and refuses a longer set.
- The set must go to failure. The equations assume reps to fatigue. If you stopped with reps left, the estimate reads low. I found no 10-rep value for an RPE option, so there isn't one[9].
- Lifters misjudge failure. A pooled analysis of 12 studies (414 people) found lifters under-predicted their reps in reserve by 0.95 reps on average (95% CI 0.17 to 1.73), with considerable differences between studies[10]. I don't know how that carries over to a set you call "failure", so the page makes no adjustment for it.
- A 10RM from another set size is a stretch. The studies check the 1RM that comes out. I found none that checks a 10RM taken from the same equation, so a 10RM from a set of 3 or 8 can be off by an amount I can't quote.
- Who was studied. Mostly students and adults aged 18 to 69[2][3]. Accuracy data cover the bench press, squat and deadlift, plus the leg press. I found no data for teenagers, people over 70 or other lifts, so the calculator warns outside 18 to 69.
Testing a 10RM for Real
I did not find a protocol written for a 10RM in a primary source I could open. The Australian Institute of Sport testing manual covers 1RM, 3RM and 6RM, and it is the closest published guide[11].
- Warm-up. For a 6RM bench press it uses four lighter sets at about 40 to 60%, 60 to 70%, 70 to 80% and 90% of the load you expect to lift, with reps capped at 15, 10, 10 and 6 to 8[11].
- Attempts. After the warm-up, add load in steps such as 95%, 97.5% and 100% of the predicted load until the maximum is reached. It says to aim for the result within 4 trials, not counting the warm-up[11].
- Rest. For the bench press it gives 2 to 5 minutes between attempts, and at least 2 minutes between the earlier warm-up sets[11].
- Safety. It recommends two experienced spotters for maximal bench press efforts, and says the test ends once a technical violation is seen[11].
- Readiness. It suggests avoiding severe fatigue in the 72 hours before a test and practising the lift for at least 6 sessions first[11].
Is a rep-max test gentler than a 1RM test?
One small study points that way. It tested 34 healthy men aged 19 to 32 who had done no strength training for a year. After their 4 to 6RM and 7 to 10RM tests, none reported soreness or limited exercise[4].
After the 1RM test, 6 men (17.5%) reported limited exercise and 21 (61.2%) reported soreness, as the study reports them. It's one small sample of untrained men, so take it as a hint, not a safety guarantee.
DeLorme believed a first 10RM was often an inaccurate reflection of strength[7]. In a 2003 knee extension trial of his method, the 10RM was re-measured every week[7].
The estimate from this page can serve as a starting load for the first attempt, with the error described above.
Is a 10RM Load the Best for Building Muscle?
The traditional "repetition continuum" puts muscle growth at 8 to 12 reps with 60 to 80% of 1RM[6]. A 10RM load sits inside that range on all seven equations here, but the evidence no longer treats it as a special zone.
A 2021 review found similar muscle growth across loads from about 30% of 1RM upward, and concluded there is "no ideal hypertrophy zone"[6]. It adds that moderate loads can be the most efficient, because lighter loads need many more reps and heavier loads need more sets for comparable growth.
So a 10RM is a convenient way to pick a load, not a proven optimum. I don't give sets, reps or rest prescriptions based on it, because I couldn't tie them to a specific study.
Using the Result
- If you can, use a hard set of 4 to 6 reps. Dohoney's 4 to 6RM predicted a 1RM better than a 7 to 10RM[4], and Reynolds' 5RM beat the 10RM and 20RM[3].
- Read the range, not only the average. A wide range means less reason to trust any single number.
- On the bench press or leg press, compare the measured-data panel with the range. If they disagree, treat the whole estimate as shakier.
- Use the result as a starting load, not a verdict. The AIS manual says to record the weight and reps actually lifted[11], and a rested, warmed-up set with a spotter or safety bars gives you that.
- For other rep targets, see the 5 Rep Max Calculator and the 3 Rep Max Calculator. For a full set of percentages from one lift, use the One Rep Max Calculator.
What This Page Doesn't Cover
The previous version of this calculator had the items below. I removed them because I couldn't trace them to a source I could open:
- A flat 75% factor. The old tool multiplied each formula's 1RM by 0.75. The equations disagree on the share at 10 reps, and measured data differs by lift.
- Strength levels by exercise. I found no sourced 10RM standards, and any fixed table would ignore bodyweight.
- A table of reps at each percent up to 25 reps. The equations were built on 10 reps or fewer, so I have no support for reps beyond that.
- Claims that a 10RM maximises muscle growth, burns fat or suits a weekly split. None tied to a specific study. The one review I checked says there is no ideal hypertrophy zone[6].
- An RPE option for 10 reps. The Helms RPE chart stops at 8 reps and is based on the back squat[9], so it has no 10-rep value.
- The word "most accurate" for the average of all formulas. I found no study that tested the average.
Also unverified: the original sources for the Epley, Lander, Lombardi, Mayhew, O'Conner and Wathan equations, which I read only through LeSuer.
I know DeLorme's papers only through a 2003 trial paper and an abstract. The AIS page links a file named "v3", but the document inside is labelled Version 2.0, effective July 2022, so that is the version cited here.
Frequently Asked Questions
Sources & References
- Strength testing: predicting a one-rep max from reps-to-fatigue. Brzycki M. Journal of Physical Education, Recreation & Dance 64(1):88-90 (1993)
- The accuracy of prediction equations for estimating 1-RM performance in the bench press, squat, and deadlift. LeSuer DA, McCormick JH, Mayhew JL, Wasserstein RL, Arnold MD. Journal of Strength and Conditioning Research 11(4):211-213 (1997)
- Prediction of one repetition maximum strength from multiple repetition maximum testing and anthropometry. Reynolds JM, Gordon TJ, Robergs RA. Journal of Strength and Conditioning Research 20(3):584-592 (2006)
- Prediction of one repetition maximum (1-RM) strength from a 4-6 RM and a 7-10 RM submaximal strength test in healthy young adult males. Dohoney P, Chromiak JA, Lemire D, Abadie BR, Kovacs C. Journal of Exercise Physiology online 5(3):54-59 (2002)
- Accuracy of prediction equations for determining one repetition maximum bench press in women before and after resistance training. Mayhew JL, Johnson BD, LaMonte MJ, Lauber D, Kemmler W. Journal of Strength and Conditioning Research 22(5):1570-1577 (2008)
- Loading recommendations for muscle strength, hypertrophy, and local endurance: a re-examination of the repetition continuum. Schoenfeld BJ, Grgic J, Van Every DW, Plotkin DL. Sports 9(2):32 (2021)
- Optimal resistance training: comparison of DeLorme with Oxford techniques. Fish DE, Krabak BJ, Johnson-Greene D, deLateur BJ. American Journal of Physical Medicine & Rehabilitation 82(12):903-909 (2003)
- Restoration of muscle power by heavy-resistance exercises (abstract only read). DeLorme TL. Journal of Bone and Joint Surgery 27(4):645-667 (1945)
- Application of the repetitions in reserve-based rating of perceived exertion scale for resistance training. Helms ER, Cronin J, Storey A, Zourdos MC. Strength and Conditioning Journal 38(4):42-49 (2016)
- Accuracy in predicting repetitions to task failure in resistance exercise: a scoping review and exploratory meta-analysis. Halperin I, Malleron T, Har-Nir I, Androulakis-Korakakis P, Wolf M, Fisher J, Steele J. Sports Medicine 52(2):377-390 (2022)
- National Protocols for the Assessment of Strength and Power, Version 2.0 (effective July 2022). Australian Institute of Sport and the National Institute Network. Australian Sports Commission (2022)
Certified Personal Trainer & Sports Nutritionist
NASM-certified fitness and nutrition coach with over 10 years of hands-on experience helping people build strength, lose fat, and live healthier lives. Specializing in gym-based workouts with a strong focus on lifting technique, biomechanics, and practical exercise science. Through FitLifeRegime, sharing the tools, tips, and insights that have worked for hundreds of clients — helping you start your own fitness journey with confidence and clarity.
Learn more about Manish
NASM Certified
Certified Personal Trainer & Sports Nutritionist from the National Academy of Sports Medicine
Disclaimer: This tool is for informational and personal journaling purposes only. Results are estimates based on published formulas and may vary based on individual factors such as genetics, training history, and measurement technique.