Bench Press Calculator

It estimates your bench press one-rep max (1RM) from a submaximal set: enter the weight you lifted and how many reps you did, and it projects the heaviest single you could press using four published formulas — Epley, Brzycki, Lombardi, and O'Conner. For example, 100 kg × 5 reps gives Epley 116.67 kg, Brzycki 112.50 kg, Lombardi 117.46 kg, and O'Conner 112.50 kg, for an average estimate of 114.78 kg.

None is exact — all four are regression fits to different lifter populations, so they disagree by design. Epley and Brzycki are the most cited in strength literature. Treat the average of the four as your working estimate and the min–max spread (112.50–117.46 kg in the 100 kg × 5 example) as your uncertainty band.

Each formula models fatigue differently: Epley assumes each rep costs 1/30 of your max, Brzycki fits a hyperbolic curve, Lombardi uses a power law (reps^0.10), and O'Conner adds a flat 2.5% per rep. With 100 kg × 5 reps the spread is 112.50 kg to 117.46 kg — that range is honest information, not error.

Percentages are taken off the averaged 1RM estimate. With the 114.78 kg example: 95% = 109.04 kg, 90% = 103.30 kg, 85% = 97.56 kg, 80% = 91.83 kg, 75% = 86.09 kg, 70% = 80.35 kg, 65% = 74.61 kg, 60% = 68.87 kg. Use them to pick working weights for strength, hypertrophy, or warm-up sets.

By definition your 1RM is the weight itself, so all four formulas return the entered weight unchanged (80 kg × 1 rep → 80.00 kg on every formula). Zero, negative, or fractional reps are rejected with an honest error, and the Brzycki formula refuses 37+ reps because its denominator hits zero.

Enter your target bar weight and it greedily assigns standard plates per side, largest first. Example: a 140 kg target on a 20 kg bar loads 25 + 25 + 10 kg per side. If your plate set cannot build the exact target, it tells you the closest loadable weight and the leftover remainder instead of silently rounding.

As a rough rule of thumb: below 0.75× bodyweight is building base, 0.75–1.0× is solid, 1.0–1.25× is strong, 1.25–1.5× is advanced, and above 1.5× is elite. Example: a 100 kg estimated max at 80 kg bodyweight is 1.25×, rated Advanced. These are popular benchmarks, not medical standards — they vary with sex, training age, and technique.

Yes — the unit toggle converts every input and result instantly (1 lb = 0.45359237 kg). Plate sets switch too: metric bars default to 20 kg with 25/20/15/10/5/2.5/1.25/0.5 kg plates, imperial bars to 45 lb with 45/35/25/10/5/2.5 lb plates.

The generic one-rep-max calculator covers any lift with seven formulas and a warm-up planner; the deadlift max calculator is the deadlift-specific sibling with its own plate loader. This tool is the bench-press sibling: four-formula estimate plus a bench plate loader and a bench bodyweight-ratio rater. For turning a known 1RM into a full pyramid workout, use the bench press pyramid generator — this tool estimates the max, it does not program training.

No. True-max attempts need a competent spotter or safety arms set correctly — a failed bench press rep can trap the bar on your chest or neck. These estimates exist precisely so you can train by percentages without maxing out. This tool gives educational estimates, not coaching or medical advice.