Rep Max Table Calculator
Turn one weight-for-reps set into a full 1RM through 12RM table, using the Epley or Brzycki estimation formula.
How it works
Epley: 1RM = w × (1 + reps/30) · Brzycki: 1RM = w × 36 ÷ (37 − reps) · each rep max derived by inverting the same formula
Rather than testing every rep max directly, you can lift one honest weight-for-reps set and estimate the rest. Epley and Brzycki are the two most common formulas; Epley reads slightly higher at high reps while Brzycki is popular for reps under about ten. Both are least accurate when the rep count is high, so a set of 3–6 reps gives the most reliable table. The percentages let you pick a load for any rep target from a single test.
Worked example
A 225 lb set for 5 reps by Epley: 1RM = 225 × (1 + 5/30) = 262.5 lb. Inverting gives a 3RM of about 247 lb and a 10RM of about 197 lb, filling in the whole table without extra testing.
Sources: Epley formula (Wikipedia)
Frequently asked questions
Epley or Brzycki — which should I use?
They agree closely at low reps and diverge as reps climb. Brzycki tends to be conservative above 10 reps; Epley reads a bit higher. Pick one and stay consistent so your numbers are comparable over time.
How many reps give the best estimate?
Sets of about 3–6 reps are the sweet spot. Very high-rep sets depend heavily on conditioning and pacing, so their estimates drift from your true single.
Is an estimated 1RM safe to use?
Yes — programming from an estimate avoids the injury risk of frequent true-max testing. Treat it as a working figure and confirm occasionally with a heavy single when fresh.
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Educational estimate for training planning, not medical or coaching advice. Warm up, use good form, and progress gradually — stop if you feel pain.