Blood Volume Calculator
Estimate blood volume from body weight and a selected mL per kilogram factor.
Blood Volume measurements
Enter your values, then calculate.
Result
How to calculate blood volume
This calculator estimates total blood volume from body weight, using a standard blood-volume-per-kilogram factor — a physiological estimate used in medicine and research.
How the calculation works
Blood volume = Weight × Blood volume factor ÷ 1000, converting from mL to liters.
Example
A 70 kg person with a blood volume factor of 70 mL/kg (a commonly cited average for adults): Blood volume = 70 × 70 ÷ 1000 = 4.9 liters.
Frequently asked questions
How is Result calculated?
Result = [Weight] × [Blood volume factor] ÷ 1000.
Is the Blood Volume Calculator free to use?
Yes — every calculator on Simple Calculator Tools is free, runs in your browser, and does not require an account.
Blood Volume Calculator
Blood volume = Weight × Blood volume factor ÷ 1000, converting from mL to liters.
Let's understand your blood volume result.
Calculate a result above and this guide will help you interpret it using this calculator's own formula and explanation.
Pro Tips for Blood Volume
- The blood-volume-per-kilogram factor varies somewhat by age, sex, and body composition — roughly 70 mL/kg is a commonly cited average for adults, but individual variation exists.
- This is a population-average estimate, not a substitute for direct measurement in clinical situations where precise blood volume matters.
Common Blood Volume Mistakes to Avoid
- Treating this population-average estimate as a precise individual measurement for clinical decision-making, where more precise methods are typically required.
When to Use This Calculator
This calculator estimates total blood volume from body weight, using a standard blood-volume-per-kilogram factor — a physiological estimate used in medicine and research.