Fick Cardiac Output Calculator

This Fick cardiac output calculator will come in handy if you’ve ever wanted to know how much blood your heart pumps in a minute. This article will explain how the cardiac output is computed and define it. We’ll also show you how to apply the cardiac output formula (commonly known as the Fick equation or Fick formula) and determine if the findings are within normal limits.

Cardiologists and other medical specialists investigate the heart and how it works in order to evaluate whether a patient is healthy. They start by determining how well a person’s heart distributes blood while they are at rest. Doctors are often better equipped to detect anything out of the ordinary once they have that baseline information.

Checking cardiac output, which tells doctors how efficiently a heart is doing its job, is one approach to monitor heart function. Monitoring someone’s cardiovascular performance over time is one reason to measure their cardiac output. A cardiologist may need to calculate cardiac output to tell patients how well their hearts supply oxygen-rich blood and blood pump.

Changes in cardiac output over months or years could suggest that the heart’s ability to pump blood has deteriorated. It’s crucial to figure out how well (or poorly) a person’s heart pumps blood while they’re resting. Let’s know about how to Fick cardiac output calculator or Fick equation calculator.

Fick Cardiac Output Calculator- What Is Cardiac Output?

We refer to the amount of blood pumped through your heart each minute as cardiac output. The cardiac output of the average healthy person is 4-8 liter/min. Given that we have approximately 5 liters of blood in our bodies, every drop of blood must pass through your heart at least once each minute. Isn’t it true that the heart is overworked?

The cardiac index is the amount of blood pumped per square meter of body surface area by your heart every minute. This metric is superior for comparing two people with drastically varied cardiac outputs because of weight and height variations.

You can simply determine the stroke volume using the stroke volume calculator, which is the volume of blood pumped per one heartbeat if you know your cardiac output.

Fick Cardiac Output Calculator Formula

The Fick equation is the most commonly used formula for calculating cardiac output. Therefore, our Fick cardiac output calculator is based on this formula. It goes like this:

CO = VO2 / (Ca-Cv)


  • The abbreviation denoted the consumption of pure gaseous oxygen VO2
  • Ca is the oxygen conc. in blood arteries (in mL/L)
  • Cv is the oxygen conc. in blood veins (also in mL/L). We measure it in milliliters per minute.

A spirometer can determine the amount of oxygen consumed. We commonly calculated the cardiac output as 125 ml of oxygen per minute per square meter of body surface area to get a rough estimate.

Blood oxygen saturation and blood oxygen tension are used to determine the oxygen concentration in both arterial and venous blood. It makes use of the fact that hemoglobin molecules bind practically all the oxygen in your bloodstream. a gram of hemoglobin may carry 1.34 ml of oxygen. As a result, you may determine the oxygen concentration by measuring the hemoglobin amount in blood:

C = 100 *[(Hgb * 13.4 * Sat) + (P * 0.031)]


  • C stands for the oxygen concentration in a specific blood type (arterial or venous)
  • Hgb for hemoglobin level in g/dL
  • Sat for oxygen saturation in blood, represented as a percentage
  • P for oxygen tension, measured in Torr (mm Hg).

How Do We Calculate Fick Cardiac Output?

If you want a realistic result, you must first enter some data into our Fick cardiac output calculator.

  • Simply put, your height is a measurement of how tall you are.
  • Similarly, your weight is a measure of how much you weigh.
  • Our cardiac output calculator will calculate your body surface area and oxygen intake based on these two figures.
  • Your blood test result for hemoglobin is called hemoglobin. Men’s levels range from 13.8 to 17.2 g/dL, while women’s values range from 12.1 to 15.1 g/dL.
  • The ratio of oxygen-saturated hemoglobin to total hemoglobin in your arterial blood is known as oxygen saturation (arterial blood). This number should be between 94 and 99 percent for healthy persons.
  • The partial pressure of oxygen in arterial blood is called oxygen tension. Normally, this number should be between 75 and 100 millimeters of mercury.
  • The ratio of oxygen-saturated hemoglobin to total hemoglobin in your venous blood is known as oxygen saturation (venous blood). This proportion should be between 60 and 80 percent for healthy persons.
  • The partial pressure of oxygen in venous blood is called oxygen tension (venous blood). This reading should be between 30 and 40 millimeters of mercury.
  • If you provide these numbers, the cardiac output algorithm will automatically calculate:
  • Oxygen content in arterial blood in milliliters per liter.
  • Oxygen concentration in ml/L (venous blood).
  • Cardiac output – typical levels should range between 4 and 8 L/min.
  • In healthy adults, the cardiac index ranges from 2.5 to 4 L/(minm2).

Normal Range of Cardiac Output

So far, we’ve learned that cardiac output refers to the amount of blood pumped out of the heart each minute. The average cardiac output (or CO) of a healthy adult’s heart is about 5 L per minute. The average adult now has a total blood volume of roughly 5 L. That means that while Joe is at his desk, his heart circulates his total blood volume every minute. For an organ the size of your fist, that’s a lot of effort.

We must keep in mind that everyone is unique, thus some people may have a cardiac output that is higher or lower than usual. A larger person, such as an NBA player, has a higher cardiac output than a gymnast. Therefore, determining a person’s resting or baseline cardiac output is critical.

When your physical workload increases, your heart’s workload is predicted to rise as well. Consider how your heart beats quicker and faster as you run. It’s obvious that it’s putting in more effort. When you exercise, your cardiac output might easily increase fivefold, especially when you’re working hard.

High Output

Anemia, a disorder in which your body lacks oxygen-carrying red blood cells, can cause high output. As a result, your heart beats quicker and pumps more blood. Another common cause is hyperthyroidism, which occurs when your thyroid gland produces more thyroid hormones than is required.

Sepsis is your body’s reaction to blood infections, which can result in a dangerous drop in blood pressure and organ failure. It can also produce a high cardiac output.


Cardiac output refers to the number of liters of blood flowing through the heart chambers every minute. We combine stroke volume and heart rate to create cardiac output. The first variable, stroke volume, refers to the amount of blood pumped out of the ventricles (the heart’s vast muscular chambers) with each beat. In other terms, it refers to the volume of blood pushed out by the heart each time it beats. We frequently measured the stroke volume using echocardiography.

Our Fick cardiac output calculator can help you figure out how much blood your heart pumps every minute. Hope this Fick cardiac output calculator or Fick equation calculator will help you a lot.


When is it necessary for the body to have a higher cardiac output?

Your body may demand three or four times your typical cardiac output during activity because your muscles want extra oxygen. Your heart beats faster while you exercise, allowing more blood to flow to your body. By beating harder or increasing the amount of blood that fills the left ventricle before it pumps, your heart can increase the volume of its stroke. Your heart beats quicker and stronger during exercise to increase cardiac output.

What does it mean to have a normal cardiac output?

When a person is at rest, a healthy heart with a normal cardiac output pumps roughly 5 to 6 liters of blood every minute.

What is the significance of sustaining cardiac output?

A sufficient cardiac output helps maintain blood pressure at the levels required to give oxygen-rich blood to the brain and other critical organs.

What is the reason for the rise in cardiac output?

Your heart beats quicker during activity to allow more blood to flow to your body. Raise the amount of blood that fills the left ventricle before it pumps to increase the stroke volume.

What effect does cardiac output have on performance?

Cardiac output refers to the amount of blood pumped every minute. We improve both as a result of aerobic training, which results in greater oxygen-rich blood supply to the working muscles, resulting in improved aerobic performance.

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