Bench Press Calculator — Estimate Your 1-Rep Max
Enter the weight you just lifted and the number of reps to instantly estimate your bench press one-rep max (1RM) using five established formulas — plus a ready-to-use percentage table for programming your next session.
kg
Weight unit
Average of Epley, Brzycki, Lombardi, Mayhew and O'Conner formulas
- 1
Epley formula
100 × (1 + 5 ÷ 30) = 116.7 - 2
Brzycki formula
100 × 36 ÷ (37 − 5) = 112.5 - 3
Average of 5 formulas
578.1 ÷ 5 = 115.6 kgEpley, Brzycki, Lombardi, Mayhew and O'Conner results averaged for a more robust estimate.
How does this calculator work?
Enter the weight you lifted and the reps completed; the calculator estimates your 1-rep max using Epley (w × (1 + r/30)), Brzycki, Lombardi, Mayhew and O'Conner formulas and averages them. It also outputs a percentage table (60–100% of 1RM) for programming workouts.
Formula
How this is calculated
A one-rep maximum (1RM) is the heaviest weight you can lift once with good form. Testing your true 1RM is taxing and risky, so athletes estimate it from a submaximal set — a weight they can move for several reps — using predictive formulas.
This calculator averages five widely-used models: the **Epley** formula (w × (1 + r/30)); the **Brzycki** formula (w × 36/(37 − r)), which tends to be conservative; **Lombardi** (w × r^0.10), **Mayhew** (100w / (52.2 + 41.9 × e^−0.055r)), and **O'Conner** (w × (1 + 0.025r)). No formula is perfectly accurate — all assume good technique, full range of motion, and maximal effort on each rep. Accuracy is highest when you use 1–8 reps; beyond 10 reps the predictions diverge significantly because fatigue begins to outweigh strength as the limiting factor.
The percentage table below the result shows recommended training loads at common intensities (60–100% of your estimated 1RM), which you can plug directly into most strength-training programmes such as 5/3/1, GZCLP or Texas Method.
Frequently asked questions
No single formula is definitively best for everyone. Epley and Brzycki are the most widely cited and perform well for 2–10 reps. Brzycki tends to be slightly more conservative; Epley slightly higher. Averaging multiple formulas, as this calculator does, gives a more robust estimate than any single one.
Yes — the formulas are not bench-press-specific. Enter any weight and rep count from any barbell exercise. The percentage table works the same way. However, the rep-to-max relationship can differ by exercise and individual, so treat all estimates as planning guides rather than exact numbers.
Sets of 3–6 reps give the most reliable estimates. As reps climb past 10, cardiovascular endurance and muscular endurance start limiting you before maximum strength does, so the formula increasingly overpredicts your true 1RM.
Also known as
TG we-Calculate Editorial Team. (2026). Bench Press Calculator — Estimate Your 1-Rep Max [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/bench-press-calculator
TG we-Calculate Editorial Team. "Bench Press Calculator — Estimate Your 1-Rep Max." TG we-Calculate. 2026. https://we-calculate.com/calculator/bench-press-calculator.
TG we-Calculate Editorial Team, "Bench Press Calculator — Estimate Your 1-Rep Max," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/bench-press-calculator
@misc{wecalculate_bench_press_calculator, title = {Bench Press Calculator — Estimate Your 1-Rep Max}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/bench-press-calculator}}, year = {2026}, note = {TG we-Calculate} }
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