semkuSquat and bench max calculator
Estimate one-rep max for squat, bench press or deadlift from a weight and 1–10 repetitions.
Percentage of estimated Epley 1RM
| % of 1RM | Weight (lb) |
|---|---|
| 100% | 262.5 |
| 95% | 249.4 |
| 90% | 236.3 |
| 85% | 223.1 |
| 80% | 210.0 |
| 75% | 196.9 |
| 70% | 183.8 |
| 65% | 170.6 |
| 60% | 157.5 |
| 55% | 144.4 |
| 50% | 131.3 |
Compare six other formulas
One repetition: every result equals the entered weight.
| Formula | Estimated 1RM (lb) |
|---|---|
| Epley | 262.5 |
| Brzycki | 253.1 |
| Lombardi | 264.3 |
| Mayhew | 267.8 |
| O'Conner | 253.1 |
| Wathan | 262.3 |
| Lander | 255.8 |
Sources
This later study prints the same Epley equation used by this calculator for r > 1: 1RM = w × (1 + r / 30), where w is the load and r is the number of repetitions. Boyd Epley (1985), “Poundage chart,” in Boyd Epley Workout, Body Enterprises, p. 86, is an unlinked bibliographic reference to the original chart; the linked study does not reproduce that chart.
Original article associated with the Brzycki estimate; the equation shown in Calculation rules is this calculator’s implementation, not a claim that its coefficients were transcribed verbatim from the article.
Table 1 in this later comparison study, rather than the original publications by the formula authors, prints Lander, Lombardi, Mayhew, O’Connor and Wathen equations algebraically equivalent to those used here; the table’s O’Connor and Wathen are labelled O’Conner and Wathan in this calculator. Its printed Brzycki coefficients, 1.0278 and 0.0278, are rounded decimal representations of this calculator’s coefficients, 37/36 and 1/36, respectively. Because of that coefficient rounding, displayed values can differ by 0.1 at some repetition counts.
Calculation rules
For 2–10 repetitions, the main estimate uses Epley: weight × (1 + repetitions / 30). With one repetition, every formula returns the entered weight instead; this calculator accepts only whole-number repetitions from 1 to 10.
The comparison uses the seven equations shown below, with weight w and repetitions r. Exercise type is not an input to these equations; estimates from the same set can differ, and none is a measured maximum.
| Formula | Equation for r = 2–10 |
|---|---|
| Epley | w × (1 + r / 30) |
| Brzycki | 36w / (37 − r) |
| Lombardi | w × r^0.1 |
| Mayhew | 100w / (52.2 + 41.9 × exp(−0.055r)) |
| O'Conner | w × (1 + 0.025r) |
| Wathan | 100w / (48.8 + 53.8 × exp(−0.075r)) |
| Lander | 100w / (101.3 − 2.67123r) |
Percentage loads use the unrounded main result, from 100% down to 50% in steps of 5%. Values are rounded once to one decimal place, with halfway values rounded away from zero; unit conversion uses exactly 1 lb = 0.45359237 kg.
Frequently asked questions
- What is the estimated max for 225 lb lifted five times?
- The main Epley estimate is 262.5 lb, or 119.1 kg; the Brzycki comparison is 253.1 lb.
- Does choosing squat, bench press or deadlift change the formula?
- There is no exercise selector because these equations use only weight and repetitions; the estimate does not account for lift-specific technique.
- Why do all formulas show my entered weight for one repetition?
- The calculator treats a single completed repetition as the entered one-rep weight and bypasses the prediction formulas.
- Are the percentage loads rounded to available plates?
- No. They are calculated percentages rounded to one decimal place, without rounding to a bar or plate combination.
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Calculations run in your browser without sending your calculation inputs or results to the server. See “Privacy on this page” for information about access data.