Plates & Pace

Strength one-rep max

Overhead Press 1RM Calculator

Estimate your strict press max from a set you have done, then get training weights rounded to the small plates this lift needs.

Updated · Sources

Weight unit
StrengthPress 1RM

Estimated one-rep max

57.7 kg

90% of max
52.5 kg
Equation spread
56.3-59.5
Your set
50 × 5
WorkingAverage of 7 equations for 50 kg × 5 reps = 57.7 kg

Training weights and plates

% of 1RMWeightPlates per side, 20 kg bar
100%57.5 kg15 + 2.5 + 1.25
95%55 kg15 + 2.5
90%52.5 kg15 + 1.25
85%48.8 kgn/a
80%46.3 kgn/a
75%43.8 kgn/a
70%40 kg10
65%37.5 kg5 + 2.5 + 1.25
60%35 kg5 + 2.5

Estimated rep maxes

RepsWeight
1 rep57.5 kg
2 reps55 kg
3 reps52.5 kg
4 reps51.3 kg
5 reps50 kg
6 reps48.8 kg
8 reps46.3 kg
10 reps43.8 kg
12 reps42.5 kg

How it works

Enter a recent set of strict overhead presses, with no dip or leg drive, taken close to failure. The calculator estimates your one-rep max and gives training weights, plates and rep maxes.

The overhead press moves the least weight of the main barbell lifts, so small plates matter. A 2.5 kg jump is 5% of a 50 kg press, which is why training weights here round to 1.25 kg by default.

The formula

Formula
w = weight lifted, r = reps completed

Epley      1RM = w × (1 + r ÷ 30)
Brzycki    1RM = w × 36 ÷ (37 − r)
Average    the mean of 7 published equations: Epley, Brzycki,
           Lander, Lombardi, Mayhew, O'Conner and Wathen

With 1 rep, the one-rep max is the weight lifted.

Worked example

You press 50 kg for 5 reps.

  1. Epley: 50 × (1 + 5 ÷ 30) = 58.3 kg.
  2. Brzycki: 50 × 36 ÷ (37 − 5) = 56.3 kg.
  3. The average of all seven equations is 57.7 kg.
  4. A working set at 80% is 46.2 kg, which rounds to 45 kg: 10 + 2.5 on each side of a 20 kg bar.

Small jumps and the press

Progress on the press comes in small steps. If your gym has 0.5 or 1 kg plates, round to 1 kg. If the smallest plates are 1.25 kg, the lightest jump is 2.5 kg across the bar. The rounding setting controls the weights in both tables.

Questions

Strict press or push press?

This calculator is set up for the strict press. A push press uses leg drive and moves noticeably more weight, so estimate it from push press sets only.

Seated or standing?

Either works if you stay consistent. Seated presses remove some leg and trunk involvement, so their numbers are not interchangeable with standing presses.

Why does my overhead press stall?

Mostly because the jumps are large compared with the weight. Using smaller plates, adding reps before adding weight, or working at 80 to 90% for sets of 2 to 5 all help.

How accurate is the estimate?

From 3 to 6 reps close to failure, the equations usually agree within a few percent. The Equation spread shows the range.

Add this calculator to your site

Gym, coach or blog? You can put this calculator on your own site for free. Copy the code below into your page’s HTML. The calculator updates itself whenever we improve it.

The short script lets the frame grow to fit the calculator on your page. Please keep the credit line underneath it.

Sources

  1. Brzycki M. Strength testing: predicting a one-rep max from reps-to-fatigue. Journal of Physical Education, Recreation and Dance. 1993;64(1):88-90.
  2. Mayhew JL, Ball TE, Arnold MD, Bowen JC. Relative muscular endurance performance as a predictor of bench press strength in college men and women. Journal of Applied Sport Science Research. 1992;6(4):200-206.
  3. LeSuer DA, McCormick JH, Mayhew JL, Wasserstein RL, Arnold MD. The accuracy of prediction equations for estimating 1-RM performance in the bench press, squat, and deadlift. Journal of Strength and Conditioning Research. 1997;11(4):211-213.
  4. Haff GG, Triplett NT, eds. Essentials of Strength Training and Conditioning. 4th ed. Human Kinetics; 2016. Percentage of 1RM and repetitions allowed.