Reps convert to a one-rep max because a set has a predictable ceiling
That is Epley's formula, the most widely used one. Brzycki takes a different route — weight × 36 ÷ (37 − reps) — and reads a little lower. Both work best from 1 to 10 reps; above that the error climbs to 10–15 percent, and neither means anything past 30 reps.
Training percentages: what each rep count is worth
Programs like 5/3/1 and Starting Strength prescribe loads as a share of your 1RM. This is the standard chart tying reps to that percentage.
| Reps | % of 1RM | If 1RM = 225 lb |
|---|---|---|
| 1 | 100% | 225 lb |
| 2 | 97% | 218 lb |
| 3 | 94% | 212 lb |
| 5 | 89% | 200 lb |
| 6 | 86% | 194 lb |
| 8 | 81% | 182 lb |
| 10 | 75% | 169 lb |
| 12 | 71% | 160 lb |
A clean set of 5 sits near 87–89 percent of your max; a set of 10 is about three-quarters of it.
Where these estimates go wrong
- High reps drift. Past 10 reps the formulas overshoot; a set of 15 is muscular endurance, not a strength test. Test in the 3–6 rep range for the tightest estimate.
- Gym max ≠ competition max. A touch-and-go rep is usually 5–10 percent heavier than a paused rep, so a calculated max off touch-and-go sets flatters you.
- Warm up first. These formulas assume the set was near failure but not on fatigued, cold muscles. Estimate from a good working set, not the last grinder of the day.
Common questions
How do I estimate my bench press max?
Take the weight you lifted and multiply by (1 + reps divided by 30). That is the Epley formula. For 185 lb for 8 reps: 185 x (1 + 8/30) = 234 lb estimated max.
Is Epley or Brzycki more accurate?
Both land within about 5 percent of each other for 1 to 10 reps. Epley reads slightly higher at high reps; Brzycki is more conservative. Neither is reliable past about 10 reps.
What is a good bench press for my body weight?
For men, benching your body weight once is roughly intermediate, and 1.5 times body weight is advanced. Female lifters typically bench 50 to 60 percent of what men lift at the same body weight.
