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One Rep Max Calculator

Estimate the most you could lift for a single rep from any hard set, then get the exact weights for every training percentage. Works for bench press, squat, deadlift and any barbell lift.

Units
lb
reps
How hard was the set?

Most accurate with a set of 2–10 reps. Not to failure? Say how many reps you had left.

Estimated one rep max

115lb

Average of 7 formulas · Epley 117 · Brzycki 113

% 1RMWeight≈ Reps
100%115 lb1
95%110 lb2
90%105 lb4
85%100 lb6
80%90 lb8
75%85 lb10
70%80 lb12
65%75 lb15
60%70 lb20
55%65 lb24
50%60 lb30

For your bodyweight that is Beginner on the bench press. See the full bench press standards

Load it on the bar →

Ask about programming off your max

Ask how to use this number: working weights for a program, when to retest, or why your estimated max and real max might differ.

Uses AI. Answers can be wrong; check anything important.

Why the formulas disagree at high reps

All 1RM formulas agree at one rep (it is just the weight) and stay close up to about eight. Past that, a set becomes a test of endurance as much as strength, and each formula guesses differently. Drag the reps for a 100 kg set and watch the fan open.

Epley116.7
Brzycki112.5
Lombardi117.5
Lander113.7
O'Conner112.5
Mayhew119.0
Wathan116.6

At 5 reps the formulas differ by 6.5 kg (6.5% of the lift). Close enough to program from.

Your rep maxes: what you could lift for 1 to 12 reps

The reverse of the calculator: from your estimated max, the heaviest weight you could expect to lift for each rep count, averaging the inverse Epley and Brzycki formulas and rounded to 5 lb jumps. Use it to pick a weight for a rep target.

RepsWeight% of 1RM
1115 lb100%
2110 lb95%
3105 lb93%
4105 lb90%
5100 lb87%
6100 lb85%
795 lb82%
890 lb80%
990 lb77%
1085 lb75%
1185 lb73%
1280 lb70%

Training zones by percentage

Goal% of 1RMTypical repsYour weights
Max strength / peaking85–95%1–5100–110 lb
Strength75–85%4–885–100 lb
Hypertrophy65–80%6–1575–90 lb
Technique, speed, warm-up50–65%3–1060–75 lb

Zones follow the NSCA's general load–repetition guidance; individual rep capacity at a given percentage varies, especially on the deadlift and for lower-body lifts.

The formulas

NameFormula (w = weight, r = reps)
Epley (1985)w × (1 + r / 30)
Brzycki (1993)w × 36 / (37 − r)
Lombardiw × r^0.10
Lander100w / (101.3 − 2.67123r)
O'Connerw × (1 + 0.025r)
Mayhew100w / (52.2 + 41.9e^(−0.055r))
Wathan100w / (48.8 + 53.8e^(−0.075r))

For programming, round working weights to what you can actually load: 5 lb or 2.5 kg jumps for most lifts. The RPE calculator refines the estimate when your set was not all-out.

Questions lifters ask

What if my set was not to failure?

Pick the RPE (or reps left in reserve) for the set. The calculator then treats it as a set of reps plus reps-in-reserve, which is how the RTS RPE chart estimates a max from a submaximal set.

How do I calculate my bench press max?

Choose Bench press, enter the heaviest weight you pressed and the reps. The estimate works the same way for squat and deadlift, and the result also shows your strength level for your bodyweight.

How do I calculate my one rep max?

Lift a weight for as many clean reps as you can (ideally 2–10), then plug the weight and reps into a formula such as Epley: 1RM = weight × (1 + reps ÷ 30). This calculator averages seven published formulas to smooth out their individual biases.

How accurate are 1RM calculators?

Within a few percent when the set is 10 reps or fewer and taken close to failure. Accuracy drops with higher reps because endurance starts to matter more than strength, and the formulas disagree more.

Which 1RM formula is best?

Epley and Brzycki are the most widely used and agree closely between 2 and 10 reps. Brzycki tends to read lower at higher reps, Epley higher. No single formula wins for every lift or lifter.

Is it safe to test a true one rep max?

For experienced lifters with good technique and a spotter or safety bars, yes. Beginners get nearly all the useful information from an estimated max and avoid the injury risk and fatigue of maximal attempts.

What percentage of my max should I train at?

Roughly 60–75% for sets of 8–15 (hypertrophy), 75–85% for sets of 4–8, and 85–95% for heavy singles to triples. The chart below gives the weight for every percentage of your max.

Keep calculating