407 lb works out to 4x45 per side plus the bar — call it 405 lb in practice, since gyms rarely stock the odd change. At 7 reps the formulas are starting to drift apart — 22 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 335 lb set represents about 82% of the estimated max.
Why 7 reps widens the answer
At seven reps the estimate is getting soft. The seven equations now disagree by 22 lb, 5.4% of the answer, and the disagreement is systematic rather than random: Brzycki flattens out as reps climb while Epley keeps rising, so the higher figures in the table above come from the formulas doing the most extrapolating. If you are writing a programme off this number, work from the lower half of the range.
Training loads from a 407 lb max
Programmes are written as percentages of the max, not as absolute weights. From 407 lb, rounded to the nearest 5 lb:
| Percentage | Load | Typical set |
|---|---|---|
| 95% | 385 lb | Heavy single |
| 90% | 365 lb | Doubles and triples |
| 85% | 345 lb | Sets of four to five |
| 80% | 325 lb | Sets of six |
| 75% | 305 lb | Sets of eight |
| 70% | 285 lb | Volume work, ten or more |
407 lb is 4x45 per side plus the bar, 405 lb loaded. At this load the 22 lb the formulas disagree by is bigger than a pair of 10s, which is a good argument for programming off the lower estimate — 394 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 335 lb for 7 reps; the headline figure is their median. All seven assume a set taken close to failure with clean technique. At 7 reps you are still inside the fitted band, but conditioning is now affecting the result alongside strength, and the seven have begun to curve away from each other. 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 407 lb. This is a training estimate, not medical advice.