Body Water Percentage Calculator

Use this body water percentage calculator to estimate your total body water based on your gender, weight, and age. It works for both metric and US units.

Note: This calculator estimates your body water percentage based on your weight, age, and gender. Keep in mind that individual body composition can vary. Factors such as fitness level, hydration status, and health conditions may influence the result. For the most accurate measurements, consult with a health or fitness professional.

💧 What Is Body Water Percentage?

Your body water percentage represents how much of your total body weight comes from water. On average, adult males have about 60% of their body composed of water, while females usually have around 50–55%. This value can vary based on age, fitness level, and body composition. That’s why estimating it can help you better understand your hydration and health.

⚙️ How the Body Water Percentage Calculator Works

This tool estimates your total body water (TBW) using a modified version of the Watson formula, a commonly used method in clinical and health settings. First, it converts your weight to kilograms if needed. Then, it uses your gender and age to estimate the amount of water in your body. While height typically plays a role, this calculator uses an average height assumption to keep it simple for everyday users. As a result, it offers a quick and reasonably accurate estimate without needing detailed measurements.

📉 Why Knowing Your Body Water Percentage Matters

Hydration plays a vital role in nearly every function of the human body. For instance, water helps regulate temperature, transport nutrients, remove waste, and lubricate joints. Additionally, tracking your body water can alert you to possible dehydration or imbalances. Because of this, it’s particularly useful for athletes, people following a fitness plan, or those recovering from illness.

📏 US and Metric Units Supported

This calculator works for both US and Metric systems, making it accessible no matter where you’re located. Simply switch the unit type, enter your weight and age, and select your gender. The calculator handles the conversion instantly so that you get consistent and accurate results either way.

🔗 Related Tools for Body Analysis

⚖️ BMI Calculator
📐 BSA Calculator
🍽️ Macronutrient Calculator