The bench press is the most commonly tested upper-body lift, and also one of the easiest to estimate. Finding a true one rep max means loading the bar to the limit, ideally with a spotter, and most lifters prefer to avoid that unless they have to. A hard set of 3 to 8 repetitions gives enough information to calculate it. This calculator applies six published equations and uses the one developed specifically on the bench press, the Mayhew equation, as its headline figure, then shows your relative strength and the loads for common training percentages.
How to use the bench press max calculator
- Enter the weight you lifted in kilograms or pounds, including the bar.
- Enter the repetitions you completed with good form, from 1 to 12. The closer the set was to failure, the better the estimate.
- Enter your body weight to see relative strength (your max as a multiple of body weight).
- Read the estimated one rep max from the formula suited to this lift, plus the others, and the training loads.
Bench press max formulas
O’Conner: W × (1 + 0.025 r) · Mayhew: 100 W ÷ (52.2 + 41.9 e−0.055 r) · Wathan: 100 W ÷ (48.8 + 53.8 e−0.075 r)
W is the weight lifted and r the reps. Epley (1985), Brzycki (J Phys Educ Recreat Dance 1993;64:88–90), Lombardi (1989), O’Conner et al. (1989), Mayhew et al. (J Appl Sport Sci Res 1992;6:200–206) and Wathan (1994) are the published equations; the comparison of their accuracy across the bench press, squat and deadlift is in LeSuer et al., J Strength Cond Res 1997;11:211–213. The headline figure on this page uses Mayhew.
Worked example
80 kg for 6 reps by a 80 kg lifter.
- Mayhew estimate = 97.2 kg (214 lb)
- Average of all six formulas = 95.0 kg
- Relative strength = 97.2 ÷ 80 = 1.21 × body weight
- Working weights: 90% = 87.5 kg, 80% = 77.7 kg, 70% = 68.0 kg
All six formulas for 80 kg × 6
| Formula | Estimated 1RM (kg) | (lb) |
|---|---|---|
| Epley | 96.0 kg | 212 lb |
| Brzycki | 92.9 kg | 205 lb |
| Lombardi | 95.7 kg | 211 lb |
| O’Conner | 92.0 kg | 203 lb |
| Mayhew | 97.2 kg | 214 lb |
| Wathan | 96.3 kg | 212 lb |
| Mayhew (used) | 97.2 kg | 214 lb |
Training loads from this bench press max
| % of 1RM | Load (kg) | Load (lb) | Approximate reps to failure |
|---|---|---|---|
| 95% | 92.3 kg | 204 lb | 2 |
| 90% | 87.5 kg | 193 lb | 4 |
| 85% | 82.6 kg | 182 lb | 6 |
| 80% | 77.7 kg | 171 lb | 8 |
| 75% | 72.9 kg | 161 lb | 10 |
| 70% | 68.0 kg | 150 lb | 12 |
| 60% | 58.3 kg | 129 lb | 15+ |
Why the bench press is easier to predict
Mayhew and colleagues fitted their equation in 1992 on college men and women performing the bench press, relating the number of repetitions with 70 percent of the 1RM to the maximum lifted. Because the bench press is a stable, single-joint-dominant lift with a limited range of motion, repetition counts translate into maximal strength more reliably than they do for lifts with larger technical variation. Studies comparing equations (LeSuer et al., 1997) found that accuracy varied by lift, which is why the calculator shows all six and an average. For the heaviest sets, differences between formulas of 2 to 5 percent are common.
Be consistent about technique: a pause on the chest, no bouncing and full lockout make a set count. A touch-and-go set with a bounce will overstate the estimate.
Using your estimate well
- Test on a fresh day, after a good warm-up, using a spotter or safety arms.
- Use sets of 3 to 8 reps for the best accuracy.
- Re-test every 4 to 8 weeks as strength changes.
- Use percentages for planning: 85–90% for heavy triples, 70–80% for sets of 6–10.
For other lifts see the Squat Max Calculator and Deadlift Max Calculator. Lift totals can be scored with the Wilks Calculator and DOTS Calculator, and the general One Rep Max Calculator covers any exercise. Protein needs are in the Protein Intake Calculator.
This page is for information only and is not coaching or medical advice. Use a spotter or safety bars for heavy lifts, warm up thoroughly and stop if you feel pain.
Sources
- Epley B. Poundage Chart. Boyd Epley Workout, University of Nebraska, 1985.
- Brzycki M. Strength testing — predicting a one-rep max from reps-to-fatigue. J Phys Educ Recreat Dance 1993;64:88–90.
- Mayhew JL, et al. Relative muscular endurance performance as a predictor of bench press strength in college men and women. J Appl Sport Sci Res 1992;6:200–206.
- LeSuer DA, et al. The accuracy of prediction equations for estimating 1-RM performance in the bench press, squat, and deadlift. J Strength Cond Res 1997;11:211–213.
Frequently asked questions
How do I estimate my bench press max?
Do a hard set of 3 to 8 repetitions with good form, enter the weight and reps, and the calculator estimates the one rep max. For example, 80 kg for 6 reps gives about 97 kg by the Mayhew equation.
Which formula is best for the bench press?
The Mayhew equation was developed on the bench press, and the Wathan equation also performed well on it in comparison studies. The calculator uses Mayhew as its headline figure and shows the others.
Is it safe to test a one rep max?
It carries more risk than submaximal work. Use a spotter or power rack safety pins, warm up with progressively heavier sets and stop at the first sign of form breakdown. Many lifters estimate instead of testing.
What is a good bench press?
It depends on age, sex, body weight and training history. Rather than relying on unsourced standards, track your own progress and your ratio to body weight, which this calculator displays.