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One-Rep Max Calculator
Estimate your 1RM from weight × near-failure reps with three formulas (Epley, Brzycki, Lombardi) averaged into one number — Epley is excluded at ≤2 reps because it reads ~3% high at 1 rep — plus a rep-max % training table (loads for 1–12 reps) and per-lift pages. A fitness estimate; accuracy degrades above ~10 reps. Accurate, instant and free — for United States.
What these mean:
Estimated one-rep max ≈ 258 lb from 225 lb × 5 reps — averaging Epley 263, Brzycki 253 and Lombardi 264 lb. An estimate — your reps must be near-failure and accuracy degrades above ~10 reps; general fitness guidance.
Estimated 1RM (lb)
258 lb
Epley (lb)
263 lb
Brzycki (lb)
253 lb
Lombardi (lb)
264 lb
| Reps | % of 1RM | Load (lb) |
|---|---|---|
| 1 | 100% | 258 lb |
| 2 | 97% | 250 lb |
| 3 | 94% | 243 lb |
| 4 | 92% | 237 lb |
| 5 | 89% | 230 lb |
| 6 | 86% | 222 lb |
| 7 | 83% | 214 lb |
| 8 | 81% | 209 lb |
| 9 | 79% | 204 lb |
| 10 | 77% | 199 lb |
| 11 | 75% | 194 lb |
| 12 | 73% | 188 lb |
Which formula, and why the spread?
An estimate — general fitness guidance
How we calculate this
Reviewed by Reckonist Editorial · Last reviewed July 2026. Figures follow the methods and sources set out in our editorial standards.
1RM via Epley, Brzycki and Lombardi formulas (averaged). An estimate — reps must be near-failure; general fitness guidance.
Epley / Brzycki / Lombardi · Arvo
Round out your training: pace your conditioning with the Running Pace Calculator, and set effort with the Heart-Rate Zone Calculator.
Three formulas, one averaged estimate
A one-rep max is estimated from a set you took close to failure — weight × reps run through a 1RM formula. A single formula is commodity, so this calculator shows three and averages them: Epley (best 6–10 reps), Brzycki (best 1–6 reps) and Lombardi. The spread between them tells you how precise the estimate is. Every figure carries its unit — the 1RM stays in the lb or kg you entered.
The three formulas
averaged spread
Epley = w × (1 + reps/30) · Brzycki = w × 36/(37 − reps) · Lombardi = w × reps^0.10
Brzycki best 1–6 reps, Epley best 6–10. Epley reads ~3% high at 1 rep, so it is excluded from the average at 1–2 reps.
Rep-max % table
load for 1–12 reps
load(reps) = 1RM × %(reps)
Turn your 1RM into training loads — ≈100% for 1 rep, 89% for 5, 77% for 10 — to program percentage-based sets.
- 1Epley: 225 × (1 + 5/30) = 225 × 1.1667 = 262.5 lb.
- 2Brzycki: 225 × 36 / (37 − 5) = 8100 / 32 = 253.1 lb.
- 3Average (with Lombardi 264): (262.5 + 253.1 + 264) / 3 ≈ 260 lb. A % table off that gives 89% ≈ 231 for 5 reps, 77% ≈ 200 for 10.
Turn your 1RM into training percentages
Most 1RM calculators stop at a single number. The wedge here is the rep-max % training table: once your 1RM is estimated, the tool derives the load for 1–12 repsas a percentage of that max — roughly 100% for a single, 89% for a set of 5, 77% for a set of 10. Programs are usually written as percentages of 1RM, so the table converts “5×5 at 80%” into an actual bar load in your unit.
The spread is the honesty signal
Bench, squat, deadlift and overhead press
The 1RM formulas are lift-agnostic — the same math applies to the bench press, squat, deadlift and overhead press. The lift selector labels your result, and dedicated per-lift pages exist for bench, squat and deadlift. In practice, high-rep sets on big lower-body lifts can read a little high, so a low-rep near-failure set gives the most reliable estimate on the squat and deadlift.
Reps must be near-failure; > 10 reps degrades
A 1RM estimate is only as good as the set behind it. The reps must be taken close to failure — a set with reps left in the tank under-estimates your max. Accuracy is best at low reps; above about 10 reps the formulas increasingly disagree and tend to overestimate, because high-rep performance depends on conditioning as much as raw strength.
An estimate — general fitness guidance
Frequently asked questions
Take a weight you lifted for a known number of near-failure reps and run it through a 1RM formula. Epley is 1RM = weight × (1 + reps/30); Brzycki is weight × 36/(37 − reps); Lombardi is weight × reps^0.10. For example, a 225 lb bench for 5 reps gives Epley 262.5, Brzycki 253.1 and Lombardi 264, which average to about 260 lb. This calculator computes all three and shows the estimate in the same unit (lb or kg) you entered — no conversion.
It depends on the rep range. Brzycki is most accurate for low reps (about 1–6), while Epley is better for moderate reps (about 6–10). They agree within roughly 2–3% at low reps and diverge as reps climb. Because no single formula is right for everyone, this tool shows Epley, Brzycki and Lombardi side by side and averages them — the spread between them is an honest signal of how precise (or not) the estimate is.
At exactly 1 rep, Epley returns weight × (1 + 1/30) = 1.033 × weight — about 3% higher than the actual weight you just lifted, which by definition IS your 1RM. Brzycki correctly returns weight × 36/36 = the weight itself. To avoid biasing the average upward on a true single or double, this calculator drops Epley from the average at 1–2 reps and uses Brzycki and Lombardi instead.
Once you have an estimated 1RM, the table shows the load for 1–12 reps as a percentage of that 1RM — roughly 100% for 1 rep, 89% for 5 reps, 77% for 10 reps. Programs are often written as percentages of 1RM (e.g. 5 sets of 5 at 80%), so the table converts those percentages into actual bar loads in your unit. Treat the loads as starting points and adjust to how the bar actually moves.
It is an estimate, not a tested max. Accuracy is best when your reps are taken close to failure and the rep count is low (under about 6). Above ~10 reps the formulas increasingly disagree and tend to overestimate, because rep performance at high reps depends heavily on conditioning and pain tolerance rather than pure strength. Use a low-rep, near-failure set for the most trustworthy number, and re-test periodically.
Yes — the formulas are lift-agnostic, so the same math applies to bench press, squat, deadlift, overhead press or any barbell lift. The lift selector simply labels your result. In practice, higher-rep sets on big lower-body lifts (squat, deadlift) can read a little high, so a low-rep set gives the most reliable estimate on those.
Method, formulas & references
Methodology: 1RM estimated from a near-failure set via Epley (w × (1 + reps/30)), Brzycki (w × 36/(37 − reps)) and Lombardi (w × reps^0.10), averaged — Epley excluded from the average at 1–2 reps because it reads ~3% high at 1 rep. Rep-max % table: load(reps) = 1RM × %(reps) for 1–12 reps. No unit conversion — the 1RM keeps the input unit (lb or kg). All calculations run client-side and nothing is stored. A fitness estimate — reps must be near-failure and accuracy degrades above ~10 reps. General fitness guidance.
Cross-links
How we calculate this
Reviewed by Reckonist Editorial · Last reviewed July 2026. Figures follow the methods and sources set out in our editorial standards.
1RM is estimated with the Epley, Brzycki and Lombardi formulas (averaged; Epley excluded at 1–2 reps). This is a general fitness estimate — your reps must be taken near failure and accuracy degrades above ~10 reps. General fitness guidance.
Keep going
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