The Ultimate Fitness Toolkit

Precision for your Health Journey.

BMIFatCalc provides professional-grade diagnostic tools to decode your body composition. From BMI to metabolic rates, we offer the scientific depth you need to optimize your fitness and longevity.

Clinically Validated

Our calculators utilize the most respected formulas in modern dietetics, ensuring your results are as accurate as current science allows.

100% Data Sovereignty

Zero data storage. Your measurements are processed locally in your browser, keeping your health journey strictly private.

Instant Diagnosis

No sign-ups, no paywalls. Get comprehensive breakdowns of your health status in milliseconds.

BMI Calculator

Assess your weight relative to your height. Our BMI tool provides detailed category breakdowns and health risk assessments based on WHO standards.

Start Calculating

Body Fat Percentage

Go beyond the scale. Estimate your body fat using the Navy Method and BMI Method for a more accurate picture of your physical health.

Start Calculating

BMR / TDEE

Calculate your metabolic rate and daily energy expenditure to optimize your nutrition plan.

Open Tool

Why Metrics Matter

Understanding your body is the first step toward lasting health. Our tools use validated formulas to provide insights that go deeper than just a number on a scale.

99.9%
Accuracy in Formulas
Privacy
Local Processing

About Us

Learn about our mission

Core Health Indicators Explained

Understanding these three pillars is essential for any fitness or weight management goal.

BMI (Body Mass Index)

A simple mathematical ratio that compares your weight to your height. While it doesn't measure fat directly, it serves as a critical screening tool for weight-related health risks.

Primary Use

Population-wide weight screening

Body Fat %

The percentage of your total weight that is composed of fat. This is often considered a more accurate representation of fitness than weight alone, as it accounts for muscle mass.

Primary Use

Body composition and performance

BMR (Metabolic Rate)

The number of calories your body burns just to keep you alive. Knowing your BMR is the foundation for creating a scientifically accurate nutrition plan.

Primary Use

Caloric intake and goal setting

Frequently Asked Questions

How often should I calculate my BMI and Body Fat?

Body composition changes slowly. For most people, checking these metrics once every 4 to 8 weeks is sufficient. Frequent daily checks can lead to unnecessary stress as water weight and daily fluctuations can skew results significantly. Focus on long-term trends rather than daily numbers.

Is the Navy Method accurate for body fat?

The U.S. Navy Method is highly regarded for its simplicity and surprisingly high correlation with DEXA scans (the gold standard). It generally stays within a 3-4% margin of error for most adults. While not perfect, it is one of the most reliable methods that doesn't require expensive medical equipment or specialized calipers.

Why does my BMR matter for weight loss?

Your Basal Metabolic Rate (BMR) represents the "floor" of your caloric needs. Eating significantly below your BMR for extended periods can trigger your body to downregulate its metabolism, making weight loss harder in the long run. Understanding your BMR helps you set a healthy and sustainable caloric deficit.

The Muscle Density Factor

Muscle is much denser than fat. This is why two people with the same BMI can look completely different. One may be highly athletic with high muscle mass, while the other may have higher adipose tissue. Always use BMI in conjunction with Body Fat % for a complete picture.

Metabolic Adaptation

As you lose weight, your BMR naturally decreases because there is less "you" to maintain. Re-calculating your TDEE every 5-10 lbs lost is crucial to prevent weight loss plateaus.