Sports & Fitness · Strength Training & One-Rep Max

Reverse One-Rep Max Calculator

Reverse a selected estimation equation to find the mathematical set load corresponding to an entered estimated maximum and repetition count.

Sports & Fitness

Enter your performance record

Private in-browser arithmetic · no diagnosis or training prescription

Use measured values from one consistent activity or protocol. Unit, course, equipment and timing conventions remain visible; no medical interpretation or safe training load is inferred.

Sports & Fitness result

Enter valid values to see the result.

Your entries are calculated in this browser and are not submitted to 365CALCS.COM.

Quick guide

How to use this calculator

  1. Enter measurements from one real session, race, test or equipment setup.
  2. Keep distances, timing methods, course conditions and equipment conventions consistent.
  3. Use the component results to audit the arithmetic and retain the stated limitation.

Calculation method

Calculation method

Each mode algebraically reverses its named 1RM equation.

Results describe only the entered record or scenario. They do not establish fitness, readiness, injury risk, medical safety, selection, qualification or an appropriate training plan.

Worked example

Worked example

Reversing Epley for estimated 120 at five repetitions gives about 102.86 load units.

Each mode algebraically reverses its named 1RM equation.

Supported inputs

Precision and limits

Measurement basis

Compare like with like: the same course, pool, equipment, timing convention or testing protocol where that distinction affects meaning.

No prescription

Heart-rate percentages, external load, activity intensity and workload are entered arithmetic. This page does not prescribe training or determine whether exercise is medically appropriate.

Privacy and precision

Values remain in this browser. Invalid, contradictory and non-finite states return explicit errors.

Calculator-specific boundary

This is entered-performance arithmetic, not training, medical, injury-risk, selection or fitness-for-duty advice. This is not a recommended or safe training load.

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