What's your one-rep max — and should you test it?

MOGLORD · WEB STORY How 1RM works, the safe way to estimate it, and when to test for real.

1RM = your heaviest single rep

1 1 THE DEFINITION The most weight you can lift once with clean form. It sets the percentages your whole program runs on.

2 1 WHY IT MATTERS “80% for sets of 5” means nothing without a 1RM. It turns vague effort into a plan you can progress.

3 1 THE SAFER ROUTE Do a clean set of 3–5 reps near your limit, then use Epley's formula: weight × (1 + reps ÷ 30).

4 1 WORKED EXAMPLE 225 × (1 + 5/30) = 262.5. Brzycki's formula lands close too — both are estimates, not gospel.

5 1 TESTING RULES Warm up in small jumps, rest 3–5 minutes between attempts, and take no more than 3–4 real attempts.

6 1 SAFETY Bench with a spotter or rack safeties. Squat inside the rack. A failed rep should be boring, not scary.

7 1 WHO SKIPS IT Under 6 months of training, your max changes weekly anyway. Estimates are safer and accurate enough.

THE BOTTOM LINE Estimate from a strong set; test rarely and safely. Get your 1RM from any set with the free calculator. SWIPE UP FOR THE FULL GUIDE ↓