Enter the hematocrit level and total blood volume into the calculator to determine the plasma volume; this calculator can also evaluate any of the variables given the others are known.

## Plasma Volume Formula

The following formula is used to calculate the plasma volume:

PV = (Hct * TBV) / (1 - Hct)

Variables:

- PV is the plasma volume
- Hct is the hematocrit level
- TBV is the total blood volume

To calculate the plasma volume, multiply the hematocrit level by the total blood volume, then divide the result by 1 minus the hematocrit level.

## What is a Plasma Volume?

Plasma volume refers to the amount of plasma, the liquid component of blood, circulating in the body. Plasma makes up about 55% of total blood volume and is composed primarily of water, but also contains proteins, glucose, clotting factors, electrolytes, hormones, carbon dioxide, and oxygen. It plays a crucial role in maintaining blood pressure and regulating body temperature. Plasma volume is typically measured in milliliters and can vary depending on a person’s size, hydration level, and overall health. For example, an average-sized adult male may have a plasma volume of approximately 3,000 milliliters. Changes in plasma volume can indicate various health conditions, such as dehydration, kidney disease, or heart failure.

## How to Calculate Plasma Volume?

The following steps outline how to calculate the Plasma Volume.

- First, determine the hematocrit level (%).
- Next, determine the total blood volume (TBV) in liters.
- Next, gather the formula from above = Plasma Volume = TBV * (1 – hematocrit/100).
- Finally, calculate the Plasma Volume.
- After inserting the variables and calculating the result, check your answer with the calculator above.

**Example Problem : **

Use the following variables as an example problem to test your knowledge.

hematocrit level (%) = 45

total blood volume (TBV) in liters = 5