585 lb works out to 6x45 per side plus the bar — call it 585 lb in practice, since gyms rarely stock the odd change. At 9 reps the formulas are starting to drift apart — 40 lb between the lowest and highest here — which is the method telling you the estimate is getting soft. Treat the lower end as the safer number. Your 455 lb set represents about 78% of the estimated max.
Why 9 reps widens the answer
Nine reps is near the outer limit of what these equations were fitted on, and it shows: 40 lb separates the lowest and highest estimate. A nine-rep set is shaped by conditioning, breathing and tolerance for discomfort, none of which is what a single measures. Treat 585 lb as a rough ceiling for planning, and re-test with a set of four or five before you believe it.
Training loads from a 585 lb max
Programmes are written as percentages of the max, not as absolute weights. From 585 lb, rounded to the nearest 5 lb:
| Percentage | Load | Typical set |
|---|---|---|
| 95% | 555 lb | Heavy single |
| 90% | 525 lb | Doubles and triples |
| 85% | 495 lb | Sets of four to five |
| 80% | 470 lb | Sets of six |
| 75% | 440 lb | Sets of eight |
| 70% | 410 lb | Volume work, ten or more |
585 lb is 6x45 per side plus the bar, 585 lb loaded. At this load the 40 lb the formulas disagree by is bigger than a pair of 10s, which is a good argument for programming off the lower estimate — 557 lb — and letting the bar prove you wrong rather than the other way round. Warm-up jumps also get long here; work up in percentages rather than in fixed plate increments.
The formulas behind this answer, and their limitations
The table above the fold is Epley (1985), Brzycki (1993), Lombardi (1989), O'Conner (1989), Wathan (1994), Lander (1985) and Mayhew (1992), each applied to 455 lb for 9 reps; the headline figure is their median. All seven assume a set taken close to failure with clean technique. At 9 reps you are at the top of the band these equations were fitted on, and beyond it they diverge fast, so 585 lb is a ceiling rather than a target. They also under-rate strong, experienced lifters, who hold a higher percentage of max at any rep count than the regression average. The full account — the populations behind each equation, what a bounced rep does to it, and why we stop at ten reps — is set out on the methodology page. Warm up thoroughly and use safety bars or a spotter before going anywhere near 585 lb. This is a training estimate, not medical advice.