One Rep Max for 280 lbs × 4 reps

One Rep Max Calculator
One Rep Max for
lifted for
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What is the one rep max for 280 lbs × 4 reps?

Answer

Lifting 280 lbs for 4 reps gives an estimated one rep max of
317.3 lbs

A set of 4 reps at 280 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:

280 × (1 + 4 ÷ 30)

≈

280 × 1.1333

≈

317.3 lbs

Training Weights as a % of 1RM

Percentages of your estimated max of 317.3 lbs, the way most strength programmes prescribe load:

% of 1RMWorking Weight
95%301.5 lbs
90%285.6 lbs
85%269.7 lbs
80%253.9 lbs
75%238 lbs
70%222.1 lbs
65%206.3 lbs
60%190.4 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 280 lbs × 4 reps:

FormulaEstimated 1RM
Epley317.3 lbs
Brzycki305.5 lbs
Lombardi321.6 lbs
O'Conner308 lbs
Wathan317.4 lbs
Lander309 lbs
Mayhew326.2 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 280 lbs × 4 reps? (The answer is: 317.3 lbs). Enter the weight you lifted (e.g. 280), pick pounds or kilograms, and enter how many reps you managed (e.g. 4).
Recalculate with different values ↑

One Rep Max Table for 280 lbs

RepsOne Rep Max% of 1RM
2 reps298.7 lbs93.8%
3 reps308 lbs90.9%
4 reps317.3 lbs88.2%
5 reps326.7 lbs85.7%
6 reps336 lbs83.3%
7 reps345.3 lbs81.1%
8 reps354.7 lbs78.9%
9 reps364 lbs76.9%
10 reps373.3 lbs75%
11 reps382.7 lbs73.2%
12 reps392 lbs71.4%

FAQ

What is the one rep max for 280 lbs × 4 reps?

Lifting 280 lbs for 4 reps gives an estimated one rep max of 317.3 lbs

How much of my max is 280 lbs for 4 reps?

280 lbs for 4 reps works out at 88.2% of an estimated one rep max of 317.3 lbs.

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

90% of 317.3 lbs is 285.6 lbs and 70% is 222.1 lbs. Heavy strength work usually sits at 85–95%, while volume and technique work sits nearer 65–75%.

See Also