One Rep Max for 320 lbs × 9 reps

One Rep Max Calculator

One Rep Max for

lifted for

reps

What is the one rep max for 320 lbs × 9 reps?

Answer

Lifting 320 lbs for 9 reps gives an estimated one rep max of
416 lbs

A set of 9 reps at 320 lbs is

76.9%

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:

320 × (1 + 9 ÷ 30)

=

320 × 1.3

=

416 lbs

Training Weights as a % of 1RM

Percentages of your estimated max of 416 lbs, the way most strength programmes prescribe load:

% of 1RMWorking Weight
95%395.2 lbs
90%374.4 lbs
85%353.6 lbs
80%332.8 lbs
75%312 lbs
70%291.2 lbs
65%270.4 lbs
60%249.6 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 320 lbs × 9 reps:

FormulaEstimated 1RM
Epley416 lbs
Brzycki411.4 lbs
Lombardi398.6 lbs
O'Conner392 lbs
Wathan421.7 lbs
Lander414.2 lbs
Mayhew411.6 lbs

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 320 lbs × 9 reps? (The answer is: 416 lbs). Enter the weight you lifted (e.g. 320), pick pounds or kilograms, and enter how many reps you managed (e.g. 9).

One Rep Max Calculator

One Rep Max for

lifted for

reps

One Rep Max Table for 320 lbs

RepsOne Rep Max% of 1RM
2 reps341.3 lbs93.8%
3 reps352 lbs90.9%
4 reps362.7 lbs88.2%
5 reps373.3 lbs85.7%
6 reps384 lbs83.3%
7 reps394.7 lbs81.1%
8 reps405.3 lbs78.9%
9 reps416 lbs76.9%
10 reps426.7 lbs75%
11 reps437.3 lbs73.2%
12 reps448 lbs71.4%

FAQ

What is the one rep max for 320 lbs × 9 reps?

Lifting 320 lbs for 9 reps gives an estimated one rep max of 416 lbs

How much of my max is 320 lbs for 9 reps?

320 lbs for 9 reps works out at 76.9% of an estimated one rep max of 416 lbs.

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

90% of 416 lbs is 374.4 lbs and 70% is 291.2 lbs. Heavy strength work usually sits at 85–95%, while volume and technique work sits nearer 65–75%.