% of 1RM for Hypertrophy: Use It Without Testing
Technical accuracy reviewed by Sophie Laurent 
There is no single percentage of 1RM for hypertrophy. In the studies analysed, light and heavy loads built similar amounts of muscle when sets were taken to failure, so what matters is how close to failure you train, not hitting an exact percentage. You also don’t need to test your max to use percentages: do one hard set of 1 to 10 reps, note the weight and reps, and estimate a theoretical 1RM with a formula like Epley’s. Below: what 1RM is, when a real test is worth it, how to do one safely, and how to use the estimate to choose loads, including with dumbbells.
For healthy adults. If you have pain, a current injury or a cardiovascular condition, ask a professional before loading to your limit.
What 1RM means, and what a theoretical 1RM is
Your 1RM (one repetition maximum) is the heaviest load you can lift for a single full repetition with correct technique. A theoretical 1RM is the same number, estimated: instead of going to your limit, you do a submaximal set and a formula converts weight and reps into the weight you could lift once.
Two widely used formulas are Epley’s [6] and Brzycki’s [7]. Our estimator uses Epley as the main value and Brzycki as a cross-check, and only up to 10 reps: beyond that the estimate becomes unreliable, so it asks you to repeat the set with a heavier load. The formulas are described on the methodology page.
Two worked examples:
- 40 kg per hand, 8 reps, set taken to failure: Epley gives about 50.7 kg, Brzycki about 49.7 kg.
- 30 kg per hand, 8 reps, but you felt you could have done 2 more: you count 10 effective reps and get about 40 kg.
With dumbbells the value is always per hand and cannot be compared with a barbell max.
When a 1RM test is worth it (and when it isn’t)
The test is a valid measurement tool: a systematic review of 32 studies found good to excellent test-retest reliability (median ICC of 0.97), regardless of experience, sex, age and exercise [1]. But “reliable” does not mean “necessary” or “safe for everyone”. The same authors note that if technique is not adequate, testing without practice may increase injury risk [1].
| Real 1RM test | Estimate from a submaximal set | |
|---|---|---|
| What it’s for | Knowing your actual record (competition, assessment) | Choosing loads for training |
| What it needs | Solid technique, a rack with safeties or a spotter | A load you can lift for 1–10 reps |
| Risk | Higher: you work at your limit for one rep | Lower: the set is submaximal |
| With dumbbells | Impractical and risky | Suitable, values per hand |
Practical training guideline, not the result of a single study.
It makes sense to test if you compete in a strength sport, have well-established technique and can count on safety equipment or an experienced spotter. It doesn’t make sense if you train at home with dumbbells, are a beginner, have nobody to spot you or feel pain: in those cases the estimate gives you almost everything you need.
How to test your 1RM safely
If you’ve decided to do it, this is a prudent sequence (practical training guidelines, not derived from a single study):
- Pick an exercise you have mastered and secure the attempt: a rack with safety bars or an experienced spotter. If you can’t, don’t test.
- Warm up with 5–10 minutes of general work and light sets of the exercise.
- Work up to your max with sets of increasing load and decreasing reps, without fatiguing yourself: the last build-up set should be heavy but leave you energy.
- Take 3 to 5 single attempts with 3–5 minutes of rest, raising the load a little at a time. Stop when technique breaks down or the bar visibly slows.
- Record the last valid attempt: complete, with clean technique. An attempt with compromised technique doesn’t count.
Stop immediately if you feel pain. If your technique isn’t stable yet, the systematic review cited above indicates that a familiarisation phase before testing may be appropriate [1].
How to estimate your 1RM without testing: submaximal sets and RIR
The estimate needs just one piece of data beyond weight and reps: how many reps you had left. That is RIR (repetitions in reserve).
| RPE | RIR | How it feels |
|---|---|---|
| 10 | 0 | Failure, couldn’t do another |
| 9 | 1 | Could have done one more |
| 8 | 2 | Could have done two more |
| 7 | 3 | Could have done three more |
The RIR-based RPE scale was proposed by Zourdos and colleagues: RPE 10 corresponds to 0 RIR, RPE 9 to 1 RIR, and so on [2]. In the study, 29 participants performed squats at different loads, and bar velocity was strongly inversely related to the reported RPE; the authors propose it as a practical tool for adjusting load in training [2]. It remains a subjective rating.
The procedure in four steps:
- Choose a load you can lift for 1 to 10 hard reps.
- Perform the set and note weight and reps.
- Note how many reps you had left (RIR) and add them to the reps you did.
- Enter the numbers in a formula. To skip the arithmetic, use our one rep max calculator.
How accurate is the estimate? A meta-regression of 269 studies and 7,289 people showed that the number of reps people can do at a given percentage of 1RM varies from person to person, and that the exercise matters: at the same percentage, people do more reps on the leg press than on the bench press [3]. Sex, age and training status have small influences by comparison [3]. Formulas therefore represent an average, not your exact value. Treat the theoretical 1RM as a starting point and correct it based on how your training goes.
1RM percentage for hypertrophy: what the research says
For hypertrophy there is no single percentage. A meta-analysis of 21 studies compared heavy loads (above 60% of 1RM) and light loads (up to 60%) and found similar muscle growth, while maximal strength increased more with heavy loads [4]. There is one condition: the included studies had participants take sets to momentary muscular failure, and the authors state that the results do not necessarily apply to training far from failure [4].
In practice, many hypertrophy programmes work between roughly 60% and 80% of 1RM (practical training guideline). With the Epley formula, 75% corresponds to about 10 reps, which is the limit of our estimator. For lighter loads, don’t rely on the percentage: use RIR. Because the effective range is wide but refers to sets taken to failure, getting close to failure consistently and progressing over time matters more than chasing the exact percentage (practical guideline).
Squat 1RM: is it worth testing?
The squat is less practical to test than other lifts: a failed attempt requires a rack with safeties or a spotter, because you can’t simply drop the load. With dumbbells at home, testing a squat max makes no sense.
On reliability, testing proved reliable for both upper and lower body [1]. On estimation, however, the exercise can change the result: at the same percentage of 1RM, people do more reps on the leg press than on the bench press [3]. So an estimate based on leg work may be less precise than one based on the bench press. A prudent approach: estimate your 1RM from a set of 3–6 reps with 1–2 reps in reserve (practical guideline) and revise it as you progress.
From 1RM to a plan: double progression
Knowing your 1RM is mainly useful for choosing a starting load. To keep your training progressing over time, double progression works well: pick a rep range (for example 8–12), train with the same load until you reach the top of the range on all sets, then move to the next load and restart from the bottom.
A small randomised study of 38 trained adults, lasting 8 weeks and focused on leg work, compared load progression with repetition progression at a fixed load. Muscle growth was similar, load progression was slightly better for maximal strength, and the authors consider repetition progression a valid option when heavier loads aren’t available [5]. These are short-term results from a small sample and should not be stretched beyond that.
With fixed-weight dumbbells the problem is real: load jumps can be large. From 14 to 16 kg is more than a 14% increase; starting from 12 reps, our planner estimates you would restart around 6 reps (a rough estimate derived from the Epley equation, not from a study). When the jump is too big or you’ve run out of loads, you can, in order (practical guidelines):
- raise the top of your rep range, up to 5 more reps;
- slow the lowering phase to about 3 seconds;
- add a 1–2 second pause at the point of maximum stretch;
- add a set;
- move to a harder variation of the same movement.
For a concrete dumbbell example, see the dumbbell shoulder workout at home and the side delt exercise guide. To apply the rules to your own case, use the double progression plan in the 1RM estimator.
Frequently asked questions
What percentage of 1RM should I use for hypertrophy?
A wide range works, as long as you take sets close to failure: in the studies analysed, light and heavy loads produced similar muscle gains, while maximal strength grew more with heavy loads [4]. In practice, many programmes sit between roughly 60% and 80% of 1RM (practical guideline).
Do I need to test my 1RM to train?
No, for most people. One hard set of 1 to 10 reps and an estimated theoretical 1RM are enough to choose your loads. A real test mainly makes sense in competition or if you want to measure your record, with solid technique and safety equipment [1].
How often should I test my 1RM?
There is no interval that suits everyone, and if you don't compete you can skip it entirely. Those who do test usually place it at the end of a training block, after a lighter week (practical guideline).
Is a theoretical 1RM reliable?
It is an average: the number of reps people can do at a given percentage of 1RM varies from person to person and from exercise to exercise [3]. Use it as a starting point and correct it based on how your training goes.
Can I test my 1RM with dumbbells?
You can, but it is impractical and risky: a failed attempt with two dumbbells is hard to manage, and the value is per hand, so it is not comparable with a barbell max. With dumbbells, an estimate from a submaximal set is the better choice.
How often should I re-estimate my 1RM?
There is no fixed rule. A practical habit is to re-estimate every 4–6 weeks, or when your best set improves clearly (practical guideline).
What is a 1RM used for?
Mainly to choose a starting load and working percentages, and to compare your strength over time. You don't have to measure it directly: an estimate from a submaximal set does that job for home training.
Sources
- Grgic J, Lazinica B, Schoenfeld BJ, et al. Test-retest reliability of the one-repetition maximum (1RM) strength assessment: a systematic review. Sports Medicine - Open. 2020;6:31. ↗ · DOI: 10.1186/s40798-020-00260-z
- Zourdos MC, et al. Novel resistance training-specific rating of perceived exertion scale measuring repetitions in reserve. Journal of Strength and Conditioning Research. 2016;30(1):267-275. ↗ · DOI: 10.1519/JSC.0000000000001049
- Nuzzo JL, Pinto MD, Nosaka K, Steele J. Maximal number of repetitions at percentages of the one repetition maximum: a meta-regression and moderator analysis of sex, age, training status, and exercise. Sports Medicine. 2024;54(2):303-321. ↗ · DOI: 10.1007/s40279-023-01937-7
- Schoenfeld BJ, Grgic J, Ogborn D, Krieger JW. Strength and hypertrophy adaptations between low- vs. high-load resistance training: a systematic review and meta-analysis. Journal of Strength and Conditioning Research. 2017;31(12):3508-3523. ↗ · DOI: 10.1519/JSC.0000000000002200
- Plotkin D, et al. Progressive overload without progressing load? The effects of load or repetition progression on muscular adaptations. PeerJ. 2022;10:e14142. ↗ · DOI: 10.7717/peerj.14142
- Epley B. Poundage Chart. Boyd Epley Workout. University of Nebraska; 1985. (Formula origin, not indexed on PubMed.)
- Brzycki M. Strength testing: predicting a one-rep max from reps-to-fatigue. Journal of Physical Education, Recreation and Dance. 1993;64(1):88-90. (Formula origin, not indexed on PubMed.)