Health & Medicine · Fitness · Strength Training
Bench Press Calculator
Estimates your one-rep maximum (1RM) bench press from a submaximal lift using the Epley, Brzycki, or Lander formula.
Calculator
Formula
w = weight lifted (kg or lb); r = number of repetitions performed to near-failure. The Epley formula is the most widely used and works well for moderate rep ranges (1–10). The Brzycki formula is accurate for lower rep ranges (1–6). The Lander formula provides an alternative regression-based estimate. All three assume the set is performed to or near muscular failure.
Source: Epley B. (1985). Poundage Chart. Boyd Epley Workout. Lincoln, NE. / Brzycki M. (1993). Strength Testing — Predicting a One-Rep Max from Reps-to-Fatigue. Journal of Physical Education, Recreation & Dance, 64(1):88–90. / Lander J. (1985). Maximums based on reps. NSCA Journal, 6(6):60–61.
How it works
A one-rep maximum is the gold standard measure of maximal strength for a given lift. However, directly testing a 1RM carries injury risk and requires significant neural fatigue, making frequent testing impractical. Predictive equations allow athletes to estimate their 1RM from a safer submaximal effort — typically a set of 2 to 10 repetitions taken to or very close to muscular failure. The closer to failure the set is taken, the more accurate the prediction.
Three formulas are widely used in strength science. The Epley formula (1985) calculates 1RM = w × (1 + r/30), where w is the load lifted and r is the number of repetitions. It is the most commonly cited equation and performs well across moderate rep ranges. The Brzycki formula uses 1RM = (w × 36) / (37 − r), which tends to be more accurate at lower rep ranges of 1–6. The Lander formula, derived from regression analysis, uses 1RM = (100 × w) / (101.3 − 2.67123 × r) and offers an empirically fitted alternative. All three formulas assume the set was performed to or near complete muscular failure — stopping several reps short will significantly underestimate your true 1RM.
Beyond simply knowing your 1RM, this calculator outputs training zone percentages. Strength coaches use these percentages to prescribe specific training intensities: 85–95% of 1RM for maximal strength work, 70–85% for hypertrophy-focused training, and 55–70% for muscular endurance and technique work. These zones are grounded in the NSCA and ACSM resistance training guidelines and are standard practice in periodised programming for athletes at all levels.
Worked example
Suppose a lifter performs a set of 5 repetitions with 100 kg on the bench press, taken to near-failure. Using each formula:
Epley: 1RM = 100 × (1 + 5/30) = 100 × 1.1667 = 116.7 kg
Brzycki: 1RM = (100 × 36) / (37 − 5) = 3600 / 32 = 112.5 kg
Lander: 1RM = (100 × 100) / (101.3 − 2.67123 × 5) = 10000 / (101.3 − 13.356) = 10000 / 87.944 = 113.7 kg
The three formulas give results within about 4 kg of each other, which is typical. Using the Epley estimate of 116.7 kg, training zones would be: 90% = 105.0 kg, 80% = 93.4 kg, 70% = 81.7 kg, 60% = 70.0 kg. A coach might prescribe 4 sets of 3 reps at 90% (105 kg) for strength development, or 4 sets of 8–10 reps at 70–75% for hypertrophy.
Limitations & notes
These formulas are statistical estimates derived from population averages and carry meaningful individual error. Accuracy degrades significantly when reps exceed 10 — at high rep counts, local muscular endurance plays a larger role than maximal strength, making 1RM predictions unreliable; most researchers recommend using sets of 1–6 reps for best accuracy. The formulas also assume the set was taken to true muscular failure or within 1 rep of it — sets stopped well short of failure will substantially underestimate your 1RM. Individual factors such as muscle fibre type composition, training age, and technique efficiency affect how well any given formula fits a particular person. These equations should be used as programming guides, not as competitive records. Additionally, this calculator does not account for body weight, gender, age-related strength decline, or equipment differences (raw vs. equipped bench press). Always consult a qualified strength and conditioning coach before attempting true maximal efforts.
Frequently asked questions
Which bench press 1RM formula is the most accurate?
Research shows no single formula is universally superior, but the Brzycki formula tends to be slightly more accurate for low rep ranges (1–6), while the Epley formula performs well across moderate ranges (3–10). A 2012 meta-analysis by Pessôa Filho et al. found all three major formulas produce comparable results when reps are kept below 10. Using 3–5 reps for your submaximal set generally yields the best prediction accuracy across all formulas.
How do I use my 1RM to program bench press training?
Standard strength and conditioning guidelines (NSCA, ACSM) prescribe training zones as percentages of 1RM. For maximal strength, use 85–95% for 1–5 reps. For hypertrophy, use 67–85% for 6–12 reps. For muscular endurance, use below 67% for 15+ reps. This calculator outputs 60%, 70%, 80%, and 90% of your estimated 1RM to help you set these training weights directly.
How often should I retest my bench press 1RM?
Most periodisation models suggest retesting or re-estimating your 1RM every 4–12 weeks, typically at the end of a training block. Retesting too frequently is counterproductive as true maximal efforts cause significant neural fatigue. Using submaximal test sets (3–6 reps to failure) every 4 weeks provides a practical, low-risk way to track strength progression without heavy neurological cost.
Can I use this calculator for other lifts like squat or deadlift?
Yes — the Epley, Brzycki, and Lander formulas are lift-agnostic and can be applied to any exercise where a meaningful 1RM exists, including squat, deadlift, overhead press, and barbell row. However, the accuracy of predictions can vary between lifts because the relationship between submaximal repetitions and maximal strength differs slightly depending on muscle group, movement pattern, and individual fibre type distribution.
What is a good bench press 1RM relative to body weight?
Strength standards vary by training age and gender. For men, general benchmarks are: untrained ~0.5× bodyweight, novice ~0.75×, intermediate ~1.0×, advanced ~1.25–1.5×, and elite ~1.75×+ body weight. For women, typical standards are roughly 60–70% of the equivalent male benchmarks. Powerlifting federation records and the Strength Level database provide detailed percentile breakdowns by gender, age, and weight class.
Last updated: 2025-01-15 · Formula verified against primary sources.