How to estimate your bench press 1 rep max
Use this bench press calculator at the top of the page. Pick pounds or kilograms, type the weight you just lifted, and type how many clean reps you completed. The 1RM updates as you type.
A clean rep means you control the bar, touch your chest, and finish the press without help from a spotter, the person ready to assist if you cannot finish. Lockout is the finish with your arms extended. Use the same technique each time, including a pause on your chest if that is how you train. The calculator cannot check your form or tell whether someone helped with the last rep. For setup and technique, see how to bench press.
Try the 225 lb × 5 example to see how it works. You will see 263 lb with Epley and 253 lb with Brzycki. If you train in kilograms, switch units. The entered weight converts, and the estimate updates. This example uses the two-plate milestone, meaning a pair of large plates on each side of the bar. The bench 225 page explains that setup.
Enter 1 to 20 reps. Sets of 2 through 10 are more useful for estimating max strength. For a single rep with no RPE adjustment, the calculator returns the weight you entered. That is only your actual max if it was the heaviest clean rep you could do. Past 10 reps, endurance has more influence, so the estimate becomes less reliable.
What 1RM and one-rep max mean
Your bench press 1 rep max, or 1RM, is the heaviest weight you could press once with good form today. An estimated max uses a lighter set to predict that weight. You have not lifted the estimate, so use it for planning, not as a result to put in your personal-record log.
A training log often stores a personal record, or PR, next to that 1RM. A PR is a best result you have already done. A 1RM estimate is a prediction from a lighter set. They can match. They often do not, especially if the last heavy session was weeks ago, or if the set you typed was easy.
You do not need to test a true bench press 1RM every week to track progress. A challenging set of 3, 5, or 8 clean reps can give you a useful estimate without another max attempt. Use the rep-max table under the result as a reference for next week's weight, then adjust for your program and how you feel.
The Epley formula behind the 1RM
The main 1RM on this page is Epley. Boyd Epley published the poundage chart in 1985 in Boyd Epley Workout. The page writes it as:
1RM = weight × (1 + reps ÷ 30)
The formula adds a portion of the lifted weight based on the full rep count. Five reps add 5 ÷ 30, which is one-sixth. A 225 lb bench press for 5 reps becomes 225 × (1 + 1/6) = 262.5 lb, shown as 263 lb. That is an estimate, not a promise you will complete 263 lb next time. The calculator handles a single unadjusted rep separately, as explained above.
Epley is the default because it is widely used and straightforward to calculate. We can also work backward from the estimate to find a weight for a target rep count. The chart does that for 1 through 12 reps:
weight at a given rep count = 1RM ÷ (1 + reps ÷ 30)
If the estimated 1RM is 263 lb, a 5-rep set is 225 lb again. A 3-rep set is about 239 lb. An 8-rep set is about 208 lb. Those chart numbers are the same Epley math. Use them to pick a bench press weight for a planned rep target.
Long sets can give a less reliable estimate. If you type 12 or 15 reps, do not assume the result is a weight you can lift or a firm upper limit. A challenging set in the 2 to 8 range is a better starting point.
Why Brzycki sits next to Epley
Matt Brzycki published a second 1RM formula in 1993 in the Journal of Physical Education, Recreation & Dance. The comparison number sits under the main result:
1RM = weight × 36 ÷ (37 − reps)
For the same 225 lb × 5 bench press, Brzycki is 225 × 36 ÷ 32 = 253 lb. That is 10 lb under Epley. Between 2 and 8 reps the two values usually stay close. Past 10 reps they spread. Brzycki also breaks down if reps approach 37, because the denominator goes to zero. This page therefore stops at 20 reps and tells you to stay in 1 to 10 when you want a tighter pair.
A third published option is Lombardi (1989): 1RM = weight × reps^0.10, from Beginning Weight Training. The result box does not print it. Use a hard set in the low-rep range and glance at Brzycki to see whether the two formulas agree.
How to read the rep-max chart
The table under the result is a rep-max chart for the 1RM you just produced. Row 1 is the estimated max. Row 5 is a 5-rep bench press at that same 1RM. If you change the weight or the reps, the chart recalculates from the new Epley 1RM.
If you entered a set of 5 reps, rows 2, 3, or 8 show estimated weights for those rep targets. Planning a 3-rep set? Start by looking at the 3-rep row. These are estimated rep-max loads, not weights guaranteed to work for several sets. An “80 percent” load from the other table will not necessarily match row 5. This chart works backward from Epley; the percentage table simply takes a share of your estimated max.
The chart shows total weight, including the bar. Check whether your gym uses a 45 lb or 20 kg bar, then work out the plates needed on each side. You may need to round the suggested weight to match the plates available.
Bench press percentage chart
The second table takes fixed percentages of your estimated max. It does not work backward to predict a rep count. The Typical use labels give examples of training at those loads, not another strength-prediction formula.
If Epley printed 263 lb, 80% is 210 lb. A program might use that for 5×5, meaning five sets of five reps. The 50–65% range can be used for warm-ups or speed work, where the aim is to move a lighter bar quickly with control. The 90–95% range is for heavy singles or doubles, sets of one or two reps. These are general examples, not a workout prescription. The weights follow your selected unit and update as you type.
Why do the two tables disagree? The rep-max table asks what weight matches n reps under Epley if this 1RM is true. The percentages table asks what 80% of that 1RM is. Epley’s 5-rep load from 263 lb is 225 lb, which is about 85% of 263, not 80%. So 5×5 at 80% is lighter than the 5-rep row. That is expected. The two models answer different questions.
Use the rep-max table when you want a load that matches a planned rep count under the same formula that produced the 1RM. Use the percentages when your program is written as 5×5 at 80% or speed work at 60%. Do not average the two numbers. Pick the model your plan actually uses.
What this 1RM estimate does not cover
This page estimates a flat barbell bench press 1RM from total weight and reps. It cannot predict it from push-ups, calculate workout calories, or rank you against other people. For a bodyweight-based reference, see the strength standards and their assumptions.
Squat, deadlift, and overhead press, where you press the weight above your head, are different lifts. For benching with the backrest raised, use the incline bench press calculator. This page stays with flat barbell bench press.
How to use the 1RM in training
Use the estimate to plan training rather than jumping straight to a max attempt. If Epley says 263 lb and Brzycki says 253 lb, starting nearer the lower number is a cautious option for your next training block, a period of planned workouts. Check it against another clean set before increasing the weights.
If you could have done more reps but leave RPE unset, the estimate may be low. If your last rep needed help or your technique changed, the estimate may overstate what you can lift cleanly. A slow but clean rep does not automatically make the estimate too high.
RPE means rating of perceived exertion: your score for how hard the set felt. RIR means reps in reserve: how many more clean reps you think you could have done. The page estimates RIR as 10 − RPE and adds it to your completed reps. A 5-rep set at RPE 8 counts as 7 effective reps. Epley, Brzycki, and both tables use that adjusted count. Leave the control on “Not logged” to use only the reps you completed.
RPE to RIR is an approximation, not a precise measurement. It depends on how well you judge your effort, especially on easier sets. The control stops at RPE 6 because large reserve estimates can inflate the result. If effective reps go past 20, the page asks you to check the input.
Warm up as you would for any heavy bench press. The estimate does not replace a spotter, a rack with safeties, or a reason to stop. A 1RM estimate is training math, not medical advice or a coaching plan.
Sources for the formulas
- Epley, B. (1985). Poundage chart. In Boyd Epley Workout. Lincoln, NE: Body Enterprises.
- Brzycki, M. (1993). Strength testing—Predicting a one-rep max from reps-to-fatigue. Journal of Physical Education, Recreation & Dance, 64(1), 88–90.
- Lombardi, V. P. (1989). Beginning Weight Training: The Safe and Effective Way. Dubuque, IA: Wm. C. Brown.
- LeSuer, D. A., McCormick, J. H., Mayhew, J. L., Wasserstein, R. L., & Arnold, M. D. (1997). The accuracy of prediction equations for estimating 1-RM performance in the bench press, squat, and deadlift. Journal of Strength and Conditioning Research, 11(4), 211–213. Cited as a comparison study; this page does not reuse its error tables.
Common questions about the 1RM estimate
Is a bench calculator the same as a bench press 1RM calculator?
On this site, yes. Both names refer to this tool. Enter the weight and reps from a set to estimate your bench press 1 rep max.
Which 1RM should I believe if the two numbers disagree?
Epley is the main estimate, and Brzycki gives you another reference. Neither result guarantees what you can lift. If they differ a lot, try using a recent clean set with fewer reps. For training, start cautiously and adjust based on how the weight moves.
Can I enter kilograms?
Yes. Switch the unit control to kilograms. The 1RM and the charts stay in kilograms until you switch back. The example button returns to 225 lb × 5 because that example is a pound-based set.
Does this page store my numbers?
No. The weight and reps stay in your browser. There is no account. Refresh the page and you are back to the 225 × 5 example.