BODY · ENERGY · EVERYDAY MEASUREMENTS
Your numbers.
A little clearer.
Free calculators with clear methods and useful context. Understand an estimate before you decide what to do with it.
32 free calculators · No account needed
START WITH YOUR QUESTION
Choose a calculator.
Body composition
Body fat calculator
Compare tape, BMI, and skinfold methods, or add a known body-fat result.
Body composition
BMI calculator
Calculate adult BMI and see the standard category ranges. A child and teen option uses CDC BMI-for-age data.
Energy
TDEE and energy requirement calculator
Compare 2023 adult energy estimates and the 2005 age-specific equations.
Nutrition
Protein calculator
Compare protein planning ranges by activity, age, goal, and body-composition basis.
Body composition
Muscle mass calculator
Estimate skeletal muscle using waist-based equations and compare body-composition components.
Body composition
Waist-to-height ratio calculator
Compare waist with height and see the waist measurement at a 0.5 ratio.
BEHIND THE NUMBERS
Understand the result.
How to take tape measurements
Use the right landmarks for your selected method.
By Body Numeral editorial team · 7 min read
How to choose an activity level
Include your whole day, not only your workouts.
By Body Numeral editorial team · 7 min read
How muscle mass is estimated
See what a waist-based muscle estimate uses and why it is different from lean mass.
By Body Numeral editorial team · 8 min read
Waist-to-Height Ratio vs BMI: What Each Number Shows
Compare the inputs, uses, and limits of two common screening numbers.
By Body Numeral editorial team · 8 min read
Protein calculator results: what the reference value means
Understand what a grams-per-kilogram reference converts and what it cannot tell you.
By Body Numeral editorial team · 9 min read
How to calculate BMI: metric and pounds-and-inches examples
Calculate body mass index from weight and height, check the units and rounding, and use the right age reference.
By Body Numeral editorial team · 11 min readBody composition
- Are smart scales accurate for body fat?
- What is ABSI? How to read A Body Shape Index result
- What does an ideal body weight calculator actually mean?
- What is body roundness index? How to read a BRI result
- BMI vs body fat percentage: what is the difference?
- Body Fat Percentage vs Fat Mass: The Difference
- Waist-to-Height Ratio vs BMI: What Each Number Shows
- What FFMI measures and what it cannot tell you
- How muscle mass is estimated
Measurement
Energy & nutrition
EVERY CALCULATOR
Browse by topic.
Body composition
- Body fat calculator
- BMI calculator
- Waist-to-height ratio calculator
- A Body Shape Index calculator
- Body roundness index (BRI) calculator
- FFMI calculator
- Ideal body weight calculator
- Muscle mass calculator
- Navy body fat calculator
- Visceral fat area calculator
- Waist-to-hip ratio calculator
- Child BMI percentile calculator
Energy
Nutrition
Fitness
Lifestyle
Utilities
A NOTE ON TRUST
Useful estimates.
Visible limits.
Know the method.
Each calculator explains its inputs, assumptions, and sources. Where research offers several equations, as for resting energy or ideal weight, you see each one side by side. An estimate is not a diagnosis.
Methods & sources →Keep control of your data.
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