How to use this calculator
- 1
Select your unit system and lift
Choose metric (kg) or imperial (lbs), then select your lift — bench press, squat, deadlift, overhead press, or other.
- 2
Enter your weight and reps
Use a weight you can lift for 3–5 clean reps with 1–2 reps left in reserve. This range gives the most accurate prediction across all five formulas.
- 3
Read your estimated 1RM
The calculator shows results from all five formulas and their average instantly. Use the average unless you know which formula tracks best for your rep range.
- 4
Use the training load table
The table below your result shows exact working weights at every percentage of your 1RM. These update in real time as you change your inputs.
What is a 1 rep max (1RM)?
Your one-rep max (1RM) is the maximum weight you can lift for a single repetition with proper form. It is the primary measure of absolute strength in powerlifting, Olympic weightlifting, and general strength training.
A 1 rep max calculator estimates this number from a submaximal effort — if you can do 5 reps at 100 kg, the formulas predict what you could lift for 1 rep. The calculated value is called an estimated 1RM (e1RM) and is preferred over true max testing for most lifters because it carries no injury risk and is more repeatable week to week.
Knowing your 1RM lets you programme training with percentage-based loading, track long-term strength progress across bench press, squat, deadlift, and overhead press, and set realistic training targets.
How accurate is a 1RM calculator?
At 3–5 reps, most formulas are within 2–5% of a true tested 1RM for compound barbell lifts. Accuracy decreases as rep count rises above 5 because muscular endurance, not just strength, starts to determine performance. Individual factors also affect accuracy:
- Muscle fibre composition: Lifters with a higher proportion of fast-twitch fibres tend to have true 1RMs slightly higher than predicted.
- Technique efficiency: Highly technical lifts like the squat and deadlift have more accuracy variation than the bench press because technique breakdown at higher reps affects rep count independently of strength.
- Exercise type: Formulas are validated primarily for barbell compound lifts. Dumbbell exercises and machines tend to give less accurate estimates.
For programming purposes, any estimate within 5% is accurate enough to set useful working weights. Re-test every 8–12 weeks to keep your percentages current.
The five 1RM formulas compared
| Formula | Equation | Best for |
|---|---|---|
| Epley (1985) | w × (1 + reps / 30) | General use — most cited in literature |
| Brzycki (1993) | w × 36 / (37 − reps) | 1–10 reps — accurate for powerlifting |
| Lombardi (1989) | w × reps^0.10 | Explosive movements — gives higher estimates |
| O'Conner (1989) | w × (1 + 0.025 × reps) | Conservative — better for higher rep ranges |
| Lander (1985) | 100w / (101.3 − 2.67 × reps) | Powerlifting data — reliable for 1–10 reps |
Example: 100 kg × 5 reps → Epley: 116.7 kg | Brzycki: 116.3 kg | Lombardi: 114.9 kg | O'Conner: 112.5 kg | Lander: 115.5 kg | Average: ~115.2 kg
How to use your 1RM for programming
Once you know your 1RM, use these percentage zones to set your working weights. The calculator shows your exact weights at each intensity in real time.
| % 1RM | Rep range | Training goal | Example programmes |
|---|---|---|---|
| 50–65% | 15–30 | Warm-up / technique / recovery | Active deload, LISS conditioning |
| 65–75% | 10–15 | Muscular endurance / hypertrophy | German volume training, pump work |
| 70–80% | 6–12 | Hypertrophy (optimal range) | 5×10, 4×8, bodybuilding splits |
| 80–85% | 4–6 | Strength + hypertrophy | 5/3/1 BBB, Texas method volume |
| 85–90% | 2–4 | Strength development | 5/3/1 main sets, Juggernaut |
| 90–95% | 1–3 | Maximal strength / peaking | Competition prep, 1RM attempts |
| 95–100% | 1 | Competition / true max | Meet day, max-effort method |
Before you test: warm-up protocol
For the most accurate submaximal test, work up to your test set gradually rather than jumping straight to your target weight. Use your estimated 1RM as a reference for the warm-up percentages below.
| Set | Load (% est. 1RM) | Reps | Rest after |
|---|---|---|---|
| Warm-up 1 | ~50% | 10 | 90 sec |
| Warm-up 2 | ~65% | 5 | 2 min |
| Warm-up 3 | ~80% | 3 | 3 min |
| Warm-up 4 | ~87% | 1–2 | 3 min |
| Test set | ~88–93% | 3–5 | — |
After the test set, enter the weight and reps above. Aim to finish with 1–2 reps still in reserve — stopping before failure gives a cleaner signal than grinding to absolute failure, which introduces fatigue as a variable.
1RM strength standards — bench, squat, and deadlift
These are approximate 1RM benchmarks relative to bodyweight for untrained to elite lifters:
| Level | Bench (× BW) | Squat (× BW) | Deadlift (× BW) |
|---|---|---|---|
| Novice (< 1 year) | 0.75× | 1.0× | 1.25× |
| Intermediate (1–3 years) | 1.0× | 1.25× | 1.5× |
| Advanced (3–5 years) | 1.25× | 1.5× | 1.75× |
| Elite (5+ years, competitive) | 1.5×+ | 2.0×+ | 2.25×+ |
Standards for males. Females are typically 0.6–0.75× these values at the same relative level. Use our Strength Ratio Calculator for a more precise assessment.
Frequently asked questions
How do I use a 1 rep max calculator?
Select your unit system (kg or lbs) and choose your lift. Enter the weight you lifted and the reps you completed. Aim for a set of 3–5 reps with 1–2 reps left in reserve for the most accurate result. The calculator shows results from all five formulas and their average instantly, plus a full training load table.
How accurate is a 1RM calculator?
At 3–5 reps, most formulas are within 2–5% of a true tested 1RM for compound barbell lifts. Accuracy decreases above 5 reps because muscular endurance, not just strength, starts to determine performance. For programming, an estimate within 5% is accurate enough to set useful working weights.
What is the difference between 1RM and e1RM?
1RM is your actual tested maximum — the most weight you can lift for one rep. e1RM (estimated 1RM) is the value predicted from a submaximal set using a formula. For most purposes, e1RM is preferred: it's safer, more repeatable, and reliable enough for percentage-based programming.
What rep range gives the most accurate 1RM estimate?
3–5 rep sets give the most accurate predictions. Above 5 reps, muscular endurance and fatigue play a larger role than raw strength. Use a weight that leaves 1–2 reps in reserve for the most reliable input.
What is the most accurate 1RM formula?
For 1–10 reps, Brzycki and Lander tend to be most accurate for powerlifting movements. Epley is the most widely cited. No single formula wins across all rep ranges — the average of all five is more reliable than any individual formula.
How do I calculate my 1 rep max bench press?
Warm up thoroughly, then perform a set with a weight you can lift for 3–8 clean reps. Record the weight and reps and enter them above. Select 'Bench Press' in the lift toggle. The calculator shows your estimated 1RM and working weights at every training intensity.
What is a good 1 rep max for bench press?
For an 80 kg male: novice 60–75 kg, intermediate 90–110 kg, advanced 120–145 kg, elite 160+ kg. For a 60 kg female: novice 30–40 kg, intermediate 50–65 kg, advanced 75–90 kg. Training age and technique matter enormously.
What is a good 1 rep max for squat?
For an 80 kg male: novice 80–100 kg, intermediate 120–150 kg, advanced 165–200 kg, elite 220+ kg. For a 60 kg female: novice 40–55 kg, intermediate 70–90 kg, advanced 105–130 kg. Squat numbers are heavily influenced by mobility, technique, and leverages.
What is a good 1 rep max for deadlift?
For an 80 kg male: novice 100–120 kg, intermediate 150–180 kg, advanced 200–240 kg, elite 260+ kg. For a 60 kg female: novice 55–70 kg, intermediate 90–115 kg, advanced 135–165 kg. Deadlift is typically the highest of the three powerlifting movements.
What is a good 1 rep max for overhead press?
Overhead press 1RM is typically 60–70% of a lifter's bench press 1RM. For an 80 kg male: novice 40–55 kg, intermediate 65–80 kg, advanced 90–110 kg, elite 120+ kg. For a 60 kg female: novice 20–30 kg, intermediate 35–50 kg, advanced 55–70 kg. The overhead press is the weakest of the four main barbell lifts.
Should I actually test my true 1RM?
For most gym-goers, a calculated 1RM from 3–5 reps is safer and sufficient. True 1RM testing requires specific warm-up protocols, a trained spotter, and carries injury risk — particularly on squat and deadlift. Reserve actual max testing for powerlifting competition preparation.
How often should I retest my 1RM?
Retest every 8–12 weeks, or at the end of a structured training block. Strength adaptations take weeks to accumulate, and frequent max testing adds fatigue without benefit. Use 3–5 rep submaximal tests more frequently to track progress without the fatigue cost.
What is the Epley formula?
Epley formula: 1RM = weight × (1 + reps / 30). For 100 kg × 5 reps: 100 × (1 + 5/30) = 116.7 kg. It's the most commonly cited formula in exercise science and slightly overestimates at higher rep ranges compared to Brzycki.
How do I use my 1RM for programming?
Use the training load table: 65–75% for hypertrophy volume, 75–85% for strength, 85–95% for maximal strength work. The calculator shows exact weights at each percentage in real time. Update your 1RM every training block as you get stronger.