One Rep Max for 40 lbs × 4 reps

One Rep Max Calculator
One Rep Max for
lifted for
reps

What is the one rep max for 40 lbs × 4 reps?

Answer

Lifting 40 lbs for 4 reps gives an estimated one rep max of
45.3 lbs

A set of 4 reps at 40 lbs is

88.2%

of your estimated one rep max

Note: this is an estimate, not a tested max. Rep-based formulas are closest at 2–6 reps and drift further apart as the set gets longer. Warm up and use a spotter before attempting a true single.

How to Calculate One Rep Max

Epley Formula: 1RM = weight × (1 + reps ÷ 30)

The Epley formula assumes that every extra repetition you can complete corresponds to roughly 3.33% more weight on the bar. Put your set into it:

40 × (1 + 4 ÷ 30)

≈

40 × 1.1333

≈

45.3 lbs

Training Weights as a % of 1RM

Percentages of your estimated max of 45.3 lbs, the way most strength programmes prescribe load:

% of 1RMWorking Weight
95%43.1 lbs
90%40.8 lbs
85%38.5 lbs
80%36.3 lbs
75%34 lbs
70%31.7 lbs
65%29.5 lbs
60%27.2 lbs

Other One Rep Max Formulas

Published 1RM formulas disagree, and the gap widens with the rep count. This page answers with Epley; here is what the others give for 40 lbs × 4 reps:

FormulaEstimated 1RM
Epley45.3 lbs
Brzycki43.6 lbs
Lombardi45.9 lbs
O'Conner44 lbs
Wathan45.3 lbs
Lander44.1 lbs
Mayhew46.6 lbs

Related Calculations

See Also

One Rep Max Calculator

This calculator estimates your one-rep max (1RM) — the heaviest weight you could lift for a single repetition — from a set you have already completed. For example, it can help you find out what is the one rep max for 40 lbs × 4 reps? (The answer is: 45.3 lbs). Enter the weight you lifted (e.g. 40), pick pounds or kilograms, and enter how many reps you managed (e.g. 4).
Recalculate with different values ↑

One Rep Max Table for 40 lbs

RepsOne Rep Max% of 1RM
2 reps42.7 lbs93.8%
3 reps44 lbs90.9%
4 reps45.3 lbs88.2%
5 reps46.7 lbs85.7%
6 reps48 lbs83.3%
7 reps49.3 lbs81.1%
8 reps50.7 lbs78.9%
9 reps52 lbs76.9%
10 reps53.3 lbs75%
11 reps54.7 lbs73.2%
12 reps56 lbs71.4%

FAQ

What is the one rep max for 40 lbs × 4 reps?

Lifting 40 lbs for 4 reps gives an estimated one rep max of 45.3 lbs

How much of my max is 40 lbs for 4 reps?

40 lbs for 4 reps works out at 88.2% of an estimated one rep max of 45.3 lbs.

What should I lift at 90% and 70% of that max?

90% of 45.3 lbs is 40.8 lbs and 70% is 31.7 lbs. Heavy strength work usually sits at 85–95%, while volume and technique work sits nearer 65–75%.

See Also