Bench Press 1RM Calculator
A bench press 1RM calculator that does two jobs: it estimates your one-rep max from any working set using the Epley, Brzycki and Lombardi formulas, then tells you exactly which plates to load on each side of the bar to hit that number. Defaults to a 45 lb Olympic bar with standard plates.
Result
| Epley | |
| Brzycki | |
| Lombardi |
Plates per side (to load the estimated 1RM)
Percentage chart
Formula & source
Brzycki: 1RM = w × 36 / (37 − r)
Lombardi: 1RM = w × r0.1
Reported max = mean of the three
Method and assumptions: Epley (1985), Brzycki (1993), and Lombardi (1989) are the named rep-based equations used here. The displayed mean is this site’s simple arithmetic summary of their estimates, not a separately validated prediction model. The spread compares equations; it is not a confidence interval for your lift. This page accepts 1–12 whole reps. The plate-loading breakdown uses standard lb or kg plates and shows any remainder.
Worked example (you can verify by hand)
Input: 185 lb × 5 reps, 45 lb bar.
- Epley: 185 × (1 + 5/30) = 215.8; Brzycki: 185 × 36/32 = 208.1; Lombardi: 185 × 50.1 = 217.3
- Average 1RM ≈ 213.7 lb
- Per side: (213.7 − 45) / 2 = 84.35 → 45 + 25 + 10 + 2.5 = 82.5, remainder 1.85 (fractional plates)
Expected output: ≈ 214 lb 1RM; load 45+25+10+2.5 per side.
Limitations — what this cannot do
- These are estimates, not measured maximum lifts. Individual error depends on the exercise, lifter, technique and effort; this site does not establish a fixed accuracy range.
- Technique, fatigue, sleep and warm-up change the real number day to day; retest or recalculate every 4–6 weeks.
- Not for beginners attempting maximal singles without a spotter and coaching — build base volume first.
- Plate math assumes standard plate sizes; calibrated plates and specialty bars differ — weigh them once if you compete.
Disclaimer: Estimates for training planning only, not medical advice. Consult a professional.
FAQ
How do I warm up for a bench 1RM test?
A common scheme: bar × 10, 50% × 8, 70% × 5, 80% × 3, 90% × 1, then attempts. Rest 3–5 minutes between heavy singles and always use a spotter.
Why do the three formulas disagree?
The equations use different relationships between weight and reps. Their spread is a comparison of methods, not a confidence interval. The arithmetic mean is this site’s summary choice, not an independently validated combined estimator.
What plates do I need for 225 lb bench?
With a 45 lb bar: (225 − 45) / 2 = 90 per side = two 45s. Enter any target in the calculator above for the exact per-side loading.
Is touch-and-go or paused bench better for testing?
Paused and touch-and-go repetitions use different techniques. Compare sets performed to the same standard; this calculator does not quantify a fixed difference between them.