ScoutMyTool

One Rep Max Calculator

Estimate your 1RM from any rep set using Epley, Brzycki & Lombardi formulas — plus a strength % chart.

Inputs

11,500
112
Most accurate at 1–10 reps

Result

Estimated 1RM (average)
214 lb
Average of 3 standard formulas
  • Epley formula216 lb
  • Brzycki formula208 lb
  • Lombardi formula217 lb
  • 95 % of 1RM (≈2 reps)203 lb
  • 90 % of 1RM (≈4 reps)192 lb
  • 85 % of 1RM (≈6 reps)182 lb
  • 80 % of 1RM (≈8 reps)171 lb
  • 75 % of 1RM (≈10 reps)160 lb
  • 70 % of 1RM (≈12 reps)150 lb

How to use this calculator

  • Pick a recent set you took to (or near) failure with good form.
  • Stay between 1 and 10 reps — accuracy degrades past that.
  • The average of all three formulas tends to be within ±5 % of the real 1RM.
  • Use the % table to program training weights.

About this tool

Your one-rep max (1RM) is the heaviest weight you can lift for a single rep with proper form. Actually testing it is risky — most lifters estimate it instead from a sub-maximal set. This calculator runs three classic formulas (Epley, Brzycki, Lombardi) and averages them, which evens out the strengths and weaknesses of each. The percentage table below tells you how heavy to load the bar for any rep range — 80 % is roughly 8 reps, 90 % is roughly 4. Use it to plan accessory work, deload weeks, and prove-out lift attempts before you actually attempt them.

Frequently asked

No single one wins. Brzycki and Epley are the best-known; Brzycki is slightly more conservative at higher reps, Epley at lower reps. Averaging all three smooths out their individual biases.

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