Fitness Calculators

Practical calculators for protein, calories, body composition and strength — with every method and limitation explained simply.

Choose a calculator below. Every result is an estimate, so each tool also explains how it works, when it is useful and where it can mislead.

Nutrition

Protein target

Estimate a sensible daily protein range from your weight and main goal.

Weight

Unit

Main goal

Enter your weight to see your range.

Energy

TDEE calculator

Estimate the calories your body uses on an average day.

Sex used in equation

Age

Weight (kg)

Height (cm)

Typical activity

Complete all fields to see your estimate.

Body composition

Navy body-fat estimate

Use a flexible tape measure. Keep it level and do not pull it tight.

Equation

Height (cm)

Neck (cm)

Waist (cm)

Enter your measurements to see an estimate.

Screening measure

BMI calculator

Calculate weight relative to height and see the standard adult category.

Weight (kg)

Height (cm)

Enter your height and weight.

Reference range

Healthy weight range

See the weight range corresponding to the standard BMI reference interval.

Height (cm)

Enter your height to see the range.

Strength

One-rep max estimate

Estimate your maximum lift from a challenging submaximal set.

Weight lifted (kg)

Repetitions (1–12)

Enter the load and completed reps.

Educational estimates only. These tools cannot diagnose health conditions or replace advice from a doctor, registered dietitian or other qualified professional. Speak to a clinician before major diet or exercise changes if you are pregnant, have kidney disease, cardiovascular concerns or another medical condition.