Blood Plasma Volume Calculator

kg
Health

Blood Plasma Volume Calculator estimates total plasma volume based on body weight. Formula: Plasma Volume (mL) ≈ 40 × Body Weight (kg); or refine by gender (males ~4.5% BW, females ~4.0% BW).

Formula

Plasma Volume (mL) = Body Weight (kg) × Gender Factor × 1000; Males: 4.5%; Females: 4%
  • Plasma = fluid component of blood (55% of total blood volume)
  • Males typically 4.5% of body weight; females 4.0%
  • Normal range: 2.75-3.5 L for males; 2.25-2.75 L for females
  • Clinical use: dehydration assessment, transfusion planning

70 kg male

Inputs
  • Body Weight: 70 kg
  • Gender: male

70 kg × 0.045 = 3.15 L (3150 mL) plasma

Frequently asked questions

What is plasma?
Liquid component of blood (water, proteins, electrolytes); comprises ~55% of total blood volume
Why is plasma volume important?
Assess hydration status, calculate transfusion volumes, monitor fluid balance