1RM Calculator

Calculate your one-rep max and training loads

Exercise data

Enter the weight lifted and the reps performed

Results

{# Ejemplo resuelto en servidor: da contenido indexable sin depender de JavaScript y ensena el formato del resultado antes de calcular. #}

Worked example: 5 reps with 100 kg

These are the loads the calculator returns with the Epley formula. Change the form values to work out your own.

Estimated 1RM (Epley) 116.7 kg

% of 1RM Load Set goal
95 % 110.0 kg 1-2 reps (Max strength)
90 % 105.0 kg 3-4 reps (Strength)
85 % 100.0 kg 5-6 reps (Strength-Power)
80 % 92.5 kg 7-8 reps (Hypertrophy)
75 % 87.5 kg 9-10 reps (Hypertrophy)
70 % 82.5 kg 11-12 reps (Hypertrophy)
65 % 75.0 kg 13-15 reps (Muscular endurance)
60 % 70.0 kg 15+ reps (Endurance)
Keep your progress with you

Do not let your next personal best disappear in a calculator

Create a free account to log workouts, routines and progress in RMTracker. Open the web app and install it from your browser.

Create a free account Open and install the app
{# Seccion de primer nivel: usa h2/h3 para que el esquema de encabezados no salte de h2 a h4 en mitad de la pagina. #}

About the formulas

Epley:

The most used formula, especially accurate for 1-6 reps

Brzycki:

Good for higher reps, up to 10 reps

Lombardi:

Conservative, useful for beginners

Note: These are estimates. Always warm up properly and consider having a training partner for real 1RM attempts. Formulas are less accurate for very high reps (>20), but can still provide a useful estimate.

What is 1RM and what is it used for?

Your one-rep max is the greatest load you could lift once with good technique. Estimating it from a demanding set helps you program intensity without testing a true maximum.

How to calculate your one-rep max

Enter the weight and repetitions from a recent set. The calculator applies your chosen formula and provides guideline loads from 60% to 95% of your 1RM.

Example: five reps with 100 kg gives an estimated 1RM of 116.7 kg with Epley. Treat it as a training reference, not a weight you must attempt.

How to use the result

  • Use higher percentages for strength blocks.
  • Use moderate loads for controlled hypertrophy work.
  • Repeat comparable sets over time to track progress.

Frequently asked questions about 1RM

Which 1RM formula should I choose?

Epley is a practical reference for short sets. Brzycki and Lombardi let you compare estimates. No formula replaces a supervised test.

Is a high-rep 1RM estimate accurate?

Estimates generally become less precise as sets get longer. Use a recent, demanding set with sound technique and relatively few repetitions.

Do I need to test my true 1RM?

No. An estimate is usually enough to program training. If you test a maximum, warm up progressively, use safety equipment and seek qualified supervision.

How this page calculates it

The calculator applies your chosen formula to the weight and repetitions you enter, rounds to the plate increment you select and derives the load table as a percentage of the estimated 1RM. No data is sent to a server: the calculation runs in your browser.

Formula sources

The three formulas used by this calculator come from the strength training literature:

  1. Epley, B. (1985). Poundage Chart. Boyd Epley Workout. Lincoln, NE: Body Enterprises.
  2. Brzycki, M. (1993). Strength testing: predicting a one-rep max from reps-to-fatigue. Journal of Physical Education, Recreation & Dance, 64(1), 88-90.
  3. Lombardi, V. P. (1989). Beginning Weight Training: The Safe and Effective Way. Dubuque, IA: Wm. C. Brown.

This tool provides a guideline estimate for training planning and is not medical advice. If you have injuries, health conditions or any doubts, consult a healthcare professional before lifting maximal loads.

Updated on

{# Enlaces cruzados entre idiomas: hacen descubribles las URLs que declara hreflang, que solo con la etiqueta quedan huerfanas. #}