Health Calculators That Explain Your ResultsBMI, Calories, Body Fat & More
Most calculators give you a number. We give you the meaning — what it says about your body, how it compares, and what to do next.
What is your ideal weight?
How many calories do you need per day?
Is your BMI healthy?
Find out instantly.
Most Popular Health Calculators
Start with the core body-composition and energy calculators. Each one shows its formula and links to a guide that explains the result.
BMI Calculator
Body Mass Index from height and weight, with the WHO adult categories explained.
Read the BMI guide →Body Fat Calculator
Estimate body fat percentage from tape measurements (U.S. Navy method).
Read the body fat guide →Waist-to-Hip Ratio
Waist ÷ hip circumference, compared with WHO risk thresholds for men and women.
Read the waist-to-hip guide →TDEE Calculator
Estimate daily energy expenditure from BMR (Mifflin–St Jeor) and activity level.
Read the TDEE guide →Protein Calculator
Daily protein target in grams from your body weight and goal.
Read the protein for muscle gain guide →Calorie Burn Calculator
Estimate calories burned by activity, duration and body weight using MET values.
Read the exercise calories guide →All 12 Calculators
Choose from our collection of free, private body and health calculators. All calculations happen in your browser — your measurements are never sent to a server.
BMI Calculator
Calculate your Body Mass Index based on height and weight
Body Fat Calculator
Estimate your body fat percentage using measurements
Waist-to-Hip Ratio
Assess health risks based on body shape measurements
Lean Body Mass
Calculate your lean mass vs fat mass composition
Body Age Calculator
Lifestyle-based body-age score (not a clinical biological age)
Ideal Weight Calculator
Find your ideal body weight using multiple formulas
Calorie Calculator
Calculate daily calorie needs for your goals
BMR & TDEE Calculator
Find your basal metabolic rate and total daily expenditure
Calorie Burn Calculator
Calculate calories burned during any activity
Water Intake Calculator
Calculate recommended daily water consumption
Macro Calculator
Get your ideal protein, carbs, and fat breakdown
Protein Calculator
Calculate your optimal daily protein intake
How It Works
Getting your body metrics is simple, fast, and completely private. No accounts and no sign-up — your measurements are processed in your browser.
Choose a Calculator
Select from our collection of body and health calculators based on what you want to measure.
Enter Your Data
Input your measurements using our simple, user-friendly forms with helpful guidance.
Get Instant Results
View your results immediately — all calculations happen privately in your browser.
Health & Fitness Guides
Learn how to use our calculators effectively and understand the science behind your health metrics.
9 Body Health Metrics That Actually Matter (2026 Guide)
Stop guessing and start measuring. This comprehensive pillar guide connects every health metric and calculator on SnapBodyCalc into a single actionable framework for lasting results.
Understanding Your BMI and What It Really Means
Your Body Mass Index (BMI) is one of the most commonly used health metrics, but what does it actually tell you? Learn how to interpret your BMI results and understand its limitations.
How to Calculate Your Daily Calorie Needs (TDEE)
Your TDEE is the total number of calories you burn each day. Understanding this number is crucial for weight loss, muscle gain, or maintaining your current weight.
Frequently Asked Questions
Quick answers to common questions about our health calculators
Popular Health Questions
Instant answers to the questions people ask most about BMI, calories, protein and body composition.
All Health Calculators in One Place
SnapBodyCalc is a free hub for health and fitness calculators — covering everything from BMI and body fat percentage to daily calorie needs, TDEE, macros, and protein intake.
All calculations run entirely in your browser — your data stays secure and private with no account required. We use published formulas, including the Mifflin-St Jeor equation for metabolic rate, the U.S. Navy body fat formula, and multiple ideal weight calculations (Devine, Hamwi, Robinson).
Whether you're tracking your water intake, estimating calories burned during exercise, checking your waist-to-hip ratio, or calculating your lean body mass — SnapBodyCalc gives you accurate, instant results. Read our Ultimate Guide to Body Health Metrics to learn how these numbers work together.
Ready to Track Your Health Metrics?
Start using our free calculators today. No signup required, completely private, and always accessible.