Smart, Accurate & Science-Based Health Tools

Stop guessing. Start tracking. Use our 36+ free calculators to optimize your nutrition, training, pregnancy journey, and long-term health.

Why Trust Free Fitness Calculators?

We don't just give you a number. We explain the science, the formulas (like Mifflin-St Jeor & US Navy), and how to actually use the data.

Your health data stays on your device. We do not store, track, or sell your personal measurements.

We use the same equations used by dietitians and doctors (WHO, CDC, ACSM guidelines) for maximum accuracy.

We combine raw math with smart logic to give you personalized ranges and actionable tips, not just static numbers.

From TDEE to Macro splits, our tools talk the same language, making your planning seamless.

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The foundational calculators for any health journey.

Official WHO weight categories.

US Navy & BMI methods.

Weight loss & gain targets.

Total daily energy expenditure.

Optimal intake for muscle.

Weeks, trimesters & milestones.

Carb, Protein & Fat splits.

Hydration based on activity.

Find specific tools tailored to your life stage and goals.

Fitness & Strength

Diet & Nutrition

Pregnancy & Fertility

Health & Medical

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We pair every calculator with detailed guides so you understand the why behind the what.