Body Fat Calculator vs TDEE & Calorie Calculator
Both tools are 100% free, browser-based, and require no signup. Here is how they differ so you can pick the right one for your task.
Body Fat Calculator
Free body fat percentage calculator. Uses 3 methods side-by-side: the US Navy formula, a BMI-based estimate, and a skinfold-based estimate — with confidence ranges for each. No signup.
Use Body Fat Calculator →TDEE & Calorie Calculator
Free TDEE and calorie calculator. Enter your stats and activity level to get your BMR, maintenance calories, and daily calorie targets for cutting, maintaining, or bulking — with macro breakdowns. No signup.
Use Calorie Calculator →Feature Comparison
| Feature | Body Fat Calculator | Calorie Calculator |
|---|---|---|
| US Navy circumference method (neck, waist, hip) | ✓ | — |
| BMI-based body fat estimate (Deurenberg formula) | ✓ | — |
| Skinfold method explanation with confidence context | ✓ | — |
| All 3 methods shown side-by-side with confidence ranges | ✓ | — |
| Body fat category ratings (essential, athletic, fitness, average, obese) | ✓ | — |
| Metric and imperial inputs | ✓ | — |
| 100% browser-based — no data sent anywhere | ✓ | — |
| BMR using Mifflin-St Jeor equation (most accurate for most adults) | — | ✓ |
| All 5 activity levels shown side-by-side for easy comparison | — | ✓ |
| Goal-specific calorie targets: cut, maintain, or bulk | — | ✓ |
| Macro breakdown (protein, carbs, fat) per goal | — | ✓ |
| Metric (kg/cm) and imperial (lb/ft+in) support | — | ✓ |
| Shareable URL with preset inputs | — | ✓ |
| 100% browser-based — your data never leaves your device | — | ✓ |
| 100% free — no signup, no watermarks | ✓ | ✓ |
| Browser-based — files never uploaded | ✓ | ✓ |
When to Use Each Tool
- →Input neck, waist, and (if female) hip circumferences. Choose metric (cm) or imperial (inches).
- →These are needed for the BMI-based method and to display lean mass.
- →See the Navy, BMI-based, and skinfold method results side-by-side with their confidence ranges.
- →Input your weight, height, age, and sex. Toggle between metric and imperial as needed.
- →Compare all 5 activity levels side-by-side. Select the one that matches your lifestyle.
- →Select Cut, Maintain, or Bulk to see your daily calorie target and macro breakdown for that goal.
Frequently Asked Questions
The US Navy circumference method estimates body fat using neck, waist, and (for women) hip measurements. For men: %BF = 86.010 × log10(waist − neck) − 70.041 × log10(height) + 36.76. For women: %BF = 163.205 × log10(waist + hip − neck) − 97.684 × log10(height) − 78.387. It typically estimates within ±3–4% of DEXA scan results.
DEXA (dual-energy X-ray absorptiometry) and hydrostatic weighing are the gold standards but require specialized equipment. Among field methods, the Navy circumference method is practical and reasonably accurate (±3–4%). Skinfold calipers with a trained technician are also reliable (±3%). BMI-based estimates are least accurate at the individual level but require no measurements beyond weight and height. No formula replaces a direct measurement.
TDEE stands for Total Daily Energy Expenditure — the total number of calories your body burns in a day including physical activity. It is calculated by multiplying your BMR by an activity factor. TDEE is your maintenance calorie level: eating at this number keeps your weight stable.
BMR (Basal Metabolic Rate) is the number of calories your body needs at complete rest just to maintain basic functions: breathing, circulation, organ function, and temperature regulation. It represents roughly 60–70% of your total daily calorie expenditure. This calculator uses the Mifflin-St Jeor equation, which research shows is the most accurate prediction formula for most adults.