Estimated Blood Volume Calculator

Calculate your estimated total blood volume based on your physical characteristics using established medical formulas.

How to Use This Calculator

Enter your weight and height in your preferred units
Select your gender and age
Choose a calculation method (Nadler formula is recommended for adults)
Click Calculate to see your estimated blood volume
Optional: Toggle "Show detailed breakdown" to see plasma and red blood cell volumes

Formula Used

Nadler Formula (Adults):
Males: BV = 0.3669 × Height³ + 0.03219 × Weight + 0.6041
Females: BV = 0.3561 × Height³ + 0.03308 × Weight + 0.1833

Lemmens Formula:
BV = 0.07 × Weight^0.67

Weight-based (Simplified):
Adults: BV = Weight × 70 mL/kg
Children: BV = Weight × 75-80 mL/kg

Where:

BV = Blood Volume in liters
Height = Height in meters
Weight = Weight in kilograms

Example Calculation

Real-World Scenario:

A 35-year-old male who is 180 cm tall and weighs 80 kg wants to know his estimated blood volume before donating blood.

Given:

Weight = 80 kg
Height = 180 cm (1.8 m)
Age = 35 years
Gender = Male
Method = Nadler Formula

Calculation:

BV = 0.3669 × (1.8)³ + 0.03219 × 80 + 0.6041

BV = 0.3669 × 5.832 + 2.5752 + 0.6041

BV = 2.139 + 2.5752 + 0.6041 = 5.3183 liters

Result: The estimated blood volume is 5.32 liters or 5320 mL, which is approximately 6.65% of body weight.

Why This Calculation Matters

Practical Applications

Planning for blood donation
Medication dosage calculations
Preparation for surgery
Assessing blood loss in trauma

Key Benefits

Helps determine safe blood donation amounts
Guides fluid replacement in medical situations
Provides baseline for cardiovascular health

Common Mistakes & Tips

Adult formulas like Nadler's are not accurate for children. For patients under 18, use the weight-based method with appropriate mL/kg factor (75-80 mL/kg for children, higher for infants).

Pregnancy, obesity, high altitude living, and certain medical conditions can significantly affect blood volume. These formulas provide estimates for healthy individuals and may need adjustment for special circumstances.

Frequently Asked Questions

Blood typically accounts for about 7-8% of body weight in adults (approximately 70 mL per kg). This percentage is slightly higher in children (about 8-9%) and highest in newborns (about 9-10%).

Standard blood donations collect about 450-500 mL of whole blood, which is approximately 8-10% of your total blood volume. The body replenishes this volume within 24-48 hours, though red blood cells take several weeks to replace completely.

Yes, blood volume increases significantly during pregnancy—by about 30-50% above pre-pregnancy levels. This increase supports the growing fetus and prepares for blood loss during delivery. The calculator estimates for non-pregnant individuals and would need adjustment for pregnant patients.

References & Disclaimer

Medical Disclaimer

This calculator provides estimates of blood volume for informational purposes only. These calculations are not a substitute for professional medical advice, diagnosis, or treatment. Always consult with a qualified healthcare provider for medical concerns.

References

Nadler SB, Hidalgo JU, Bloch T. "Prediction of blood volume in normal human adults" - Surgery, 1962
Lemmens HJ, Bernstein DP, Brodsky JB. "Estimating blood volume in obese and morbidly obese patients" - Anesthesia & Analgesia, 2006
"Blood Volume Physiology" - StatPearls, 2022

Accuracy Notice

These formulas provide estimates with approximately 10-15% accuracy for healthy individuals. Individual variations in physiology, health status, and environmental factors can cause actual blood volume to differ from calculated estimates. Clinical measurements such as indicator dilution techniques provide more accurate assessments when precise values are medically necessary.

About the Author

Kumaravel Madhavan

Web developer and data researcher creating accurate, easy-to-use calculators across health, finance, education, and construction and more. Works with subject-matter experts to ensure formulas meet trusted standards like WHO, NIH, and ISO.

Connect with LinkedIn

Tags:

health medical-clinical-calculators estimated blood volume medical body weight

Related Calculators