Article — Bench Press Calculator (1RM)
Bench Press Calculator: Epley, Brzycki, and the Math of 1RM
The bench press 1RM (one-rep max) is the heaviest weight a lifter can complete for a single repetition with full range of motion. Testing it directly is risky and exhausting, so coaches and athletes use rep-max formulas. The two standards are Epley (Boyd Epley, 1985): 1RM = weight × (1 + reps/30). And Brzycki (Matt Brzycki, 1993): 1RM = weight × 36 / (37 − reps). For 185 lb × 8 reps, Epley gives 234 lb and Brzycki 230 lb. The calculator above runs both, averages them, and reports the result against NSCA strength standards.
The LeSuer 1997 study in the Journal of Strength and Conditioning Research compared seven rep-max formulas across bench press, squat, and deadlift in trained lifters. All seven landed within 5 percent of the true 1RM in the 2-10 rep range. Above 10 reps, accuracy degrades. The percent-of-1RM rep table in the result panel uses the conventional NSCA programming chart: 5 reps at 87 percent, 8 reps at 81 percent, 10 reps at 75 percent.
What this bench press calculator estimates
The bench press is one of three powerlifting competition lifts (with squat and deadlift) and the standard test of upper-body pressing strength. A clean 1RM requires correct setup (shoulder blades retracted, slight thoracic arch, feet planted, grip width about 1.5x shoulder width), unbroken descent and ascent, and the bar touching the chest before pressing. Competition rules require a pause at the chest.
This calculator estimates 1RM from a recent set taken to failure or near-failure. Inputs: weight on the bar and reps completed. Optional body-weight input returns the 1RM-to-bodyweight ratio and a strength-level label. The calculator is unit-agnostic — toggle pounds and kilograms; the math is the same.
The heaviest raw bench press in history is Julius Maddox’s 770.5 lb (349.6 kg) from 2020, set without a bench shirt. In equipped (multi-ply) bench shirt competition, Jimmy Kolb pressed 1,320 lb (598.7 kg) in 2023 — the bench shirt itself contributes several hundred pounds of stored elastic energy at the bottom position. The raw and equipped categories are tracked as separate world records.
The Epley bench press formula
Boyd Epley was head strength coach at the University of Nebraska-Lincoln from 1969 to 2003, where he built one of the first university strength programs and trained thousands of football players. In 1985 he published the rep-max formula now known as Epley: 1RM = weight × (1 + reps/30). The 30 in the denominator was empirically fit, not derived from theory.
The formula has stuck for nearly four decades because it is simple and well-calibrated for the 2-10 rep range. At 1 rep, it collapses to 1RM = weight. At 10 reps, it predicts the set is about 75 percent of 1RM, consistent with NSCA programming. Epley slightly overestimates above 12 reps, which is why most coaches pair it with Brzycki.
The Brzycki bench press formula
Matt Brzycki published the formula in 1993 in JOPERD Volume 64, Issue 1. The formula: 1RM = weight × 36 / (37 − reps). At 1 rep it returns the weight itself. At 10 reps it estimates 75 percent of 1RM, matching Epley and the NSCA chart. At 12 reps it predicts 71 percent; at 15 reps, 65 percent.
The formula breaks down at 37 reps because the denominator (37 − reps) hits zero. Both Epley and Brzycki are validated only for sets in the strength-and-hypertrophy zone (2-12 reps). Past that, set-to-1RM relationships shift toward endurance and the formulas no longer apply.
For everyday programming, average Epley and Brzycki and round down to the nearest 5 lb. The two formulas bracket the true value tightly enough that the midpoint is a sensible programming target. Round down because the cost of slightly under-loading a set is far smaller than the cost of failing a heavy set mid-workout.
Bench press strength standards by body weight
The conventional way to measure relative bench-press strength is the 1RM-to-bodyweight ratio. Mid-weight male reference: under 0.85x = Beginner, 0.85-1.15x = Novice, 1.15-1.50x = Intermediate, 1.50-1.75x = Advanced, 1.75x+ = Elite. Female standards run roughly 60-70 percent of male values at the same body weight.
A 180 lb man at 200 lb bench is Intermediate; at 270 lb is Advanced; at 315 lb is Elite. A 130 lb woman at 100 lb is Intermediate; at 125 lb is Advanced. The ratios are not adjusted for limb length, sternum depth, or other anatomical factors that influence bench press more than other lifts.
Bench press programming with percent of 1RM
Once an estimated 1RM is in hand, training loads follow standard percentages. Strength work (1-5 rep range): 85-100% of 1RM. Hypertrophy (6-12 reps): 65-85%. Endurance (12+ reps): below 65%. Programs like 5/3/1 Wendler, Texas Method, and Sheiko all build sessions around fixed percentages, raising the training max each cycle.
A common five-week 5/3/1 bench cycle: week 1 = 5x65%, 5x75%, 5+x85%; week 2 = 3x70%, 3x80%, 3+x90%; week 3 = 5x75%, 3x85%, 1+x95%; week 4 deload. Each “+” set goes to the highest possible rep count. The estimated 1RM from this calculator substitutes directly for the training max in Wendler-style programming.
Epley 1RM = w x (1 + r/30)Brzycki 1RM = w x 36 / (37 - r)5 reps ~87% of 1RM8 reps ~81% of 1RM10 reps ~75% of 1RMMale Elite 1.75x body weightFemale Elite 1.15x body weightRaw bench WR 770.5 lb (Maddox, 2020)Bench press world records
The raw bench press world record is 770.5 lb (349.6 kg), Julius Maddox, 2020. Maddox weighed about 400 lb at the time and trains specifically for record bench-only events. The equipped (multi-ply shirt) record is much higher: 1,320 lb (598.7 kg) by Jimmy Kolb in 2023. Bench shirts store elastic energy at the bottom of the rep and can contribute 200-400 lb to the lift.
IPF raw bench records sit lower than the all-time numbers because IPF rules require a longer pause and ban most aids. The IPF open-class (120 kg+) raw record is around 600 lb (272 kg). Women’s raw bench records peak around 350 lb (160 kg) in the heaviest weight class. Most federations have moved from the older Wilks coefficient to the newer IPF GL (DOTS) formula for cross-class comparison.
The bench press is the most common cause of strength-training fatalities, almost all from solo lifters trapped under the bar. Train alone only with safety pins set just below the chest, a power rack with bottom catches, or a flat bench inside a rack designed for fail-safe drops. Failing a heavy bench press without a spotter has killed amateur lifters and even one well-known YouTube creator. The risk does not match the convenience of going to the gym alone.
Common bench press mistakes
Three slips dominate. First, extrapolating from high-rep sets: a 15-rep set with 135 lb estimates a 1RM most lifters would not approach in reality, because high-rep work tests endurance more than max strength. Stay in the 2-10 rep range for accurate 1RM estimation. Second, comparing “gym 1RM” (touch-and-go reps) with “competition 1RM” (paused at chest): the pause typically costs 5-10 percent. Third, applying male strength standards to women: female bench press standards are roughly 60-70 percent of male values at the same body weight; using male labels under-rates female lifters significantly.
- Epley = w × (1 + r/30)
- Brzycki = w × 36 / (37 − r)
- Lombardi = w × r^0.10
- Valid rep range = 2-10 (best), up to 12 (acceptable)
- 5 reps = 87% of 1RM
- 10 reps = 75% of 1RM
- Male Beginner = under 0.85x body weight
- Male Elite = 1.75x body weight or higher
- Raw world record = 770.5 lb (Julius Maddox, 2020)
- Equipped world record = 1,320 lb (Jimmy Kolb, 2023)