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One Rep Max (1RM) Calculator

Estimate maximum weight you can lift for a single rep in bench press, squat, or deadlift using Epley and Brzycki formulas.

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Interactive One Rep Max (1RM) Calculator Workspace

Live Solver
Solver Sandbox: This is a premium sandbox template for **One Rep Max (1RM) Calculator**. The calculations are pre-configured to estimate variables. Below is the responsive form.

Mathematical Formula & Variables

Equation Model1RM = Weight * (1 + Reps / 30)

Epley formula calculating maximum single rep max based on weight lifted and sub-maximal reps performed.

Variable Definitions

SymbolDescription
WeightWeight lifted in lbs or kg
RepsNumber of successful repetitions performed (1-10 reps)

How to Use the One Rep Max (1RM) Calculator

  • Enter the weight lifted in lbs or kg.
  • Enter repetitions performed (ideally between 2 and 10 reps).
  • Calculate 1RM and view percentage training load breakdown (50% to 95% of 1RM).

Practical Example Calculation

Scenario Context: Lifting 225 lbs for 5 repetitions on bench press.

Step 1: Epley formula: 225 * (1 + 5/30) = 225 * 1.1667 = 262.5 lbs.
Step 2: Brzycki formula: 225 / (1.0278 - 0.0278*5) = 255.9 lbs.
Estimated 1RM: ~260 lbs (118 kg).

Frequently Asked Questions