One Rep Max Basics: Estimate From a Clean Submaximal Set
A one-rep max worksheet is arithmetic on a set you already completed: weight lifted and repetitions, then Epley or Brzycki. This guide explains that logic plainly. It is educational training math only—not a form check, not medical clearance, and not a prescription to attempt a true maximal lift.
What an Estimated 1RM Actually Answers
The useful question is not 'Should I load a lifetime PR today?' It is 'If this set was honest and the chosen formula applies, what single-rep load does the math project?' Use estimates to plan percentages. Attempt real maxes only with experience, spotting, and appropriate coaching.
Formulas at a Glance
| Formula | Equation | Typical use | Watch-outs |
|---|---|---|---|
| Epley | w × (1 + reps/30) | Common submaximal estimator | Long sets near failure drift more |
| Brzycki | w × 36 / (37 − reps) | Alternate estimator | Avoid very high reps; denom shrinks |
How the Worksheet Orders the Math
Record a clean set
Enter weight and whole reps from 1–12 with good form.
Choose Epley or Brzycki
Compare both if you are unsure which matches your history.
Read the estimated 1RM
Keep the same units (kg or lb) as the input weight.
Program with percentages
Prefer estimated percentages over surprise max attempts.
Run the 1RM Estimator
Enter weight, reps, and formula to review an educational one-rep max:
Open One Rep Max CalculatorWorked Scenario
Lift 100 for 5 reps. Epley gives 100 × (1 + 5/30) ≈ 116.7. Brzycki gives 100 × 36 / (37 − 5) = 112.5. Neither number proves you should load that weight tomorrow.
Bottom Line
1RM basics are transparent projections from a known set. Keep estimates for programming, keep maximal attempts rare and supervised, and never let a formula override pain or safety signals.