Cardiac Index Calculator

Determines cardiac index based on cardiac output and body surface area, as a measure of the heart’s pumping function.

Refer to the text below the calculator for the variables and formulas used.


The Cardiac Index (CI) is a hemodynamic parameter that can tell how well the heart is fulfilling its function as a pump, by directly correlating the cardiac output (or the product of stroke volume and heart rate) from the left ventricle of the heart in one minute with the body surface area.

The measurement unit for this heart performance parameter is L/min/m2.


There are two ways to calculate CI: the first based on cardiac output and body surface area and the second based on stroke volume, heart rate and body surface area:

CI (L/min/m2) = CO/BSA

CI (L/min/m2) = SV x HR / BSA

The normal range of cardiac index (at rest) is 2.6 – 4.2 L/min/m2.

Where BSA (body surface area) is calculated from patient height and weight, based on Haycock formula:

BSA = 0.024265 x (Height in cm)0.3964 x (Weight in kg)0.5378


Cardiac Output (CO)
Weight
Height
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Stroke Volume (SV)
Heart Rate (HR)
Weight
Height
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Steps on how to print your input & results:

1. Fill in the calculator/tool with your values and/or your answer choices and press Calculate.

2. Then you can click on the Print button to open a PDF in a separate window with the inputs and results. You can further save the PDF or print it.

Please note that once you have closed the PDF you need to click on the Calculate button before you try opening it again, otherwise the input and/or results may not appear in the pdf.


 

About the Cardiac Index

The CI is a hemodynamic parameter frequently measured in intensive and cardiac care units. Is correlates the cardiac output (volume of blood leaving the left ventricle per minute) with the body surface area, to provide guidance on heart performance, i.e. how well the heart’s pumping works.

The measurement unit for this heart performance parameter is L/min/m2 and its values range from 2.6 to 4.2 L/min/m2 and if the CI falls below 2.2 L/min/m2, the patient may be in cardiogenic shock.

Cardiac output is indexed to the patient’s body size by dividing it to the BSA:

CI (L/min/m2) = CO/BSA = SV x HR / BSA

Where BSA (body surface area) is calculated from patient height and weight, based on Haycock formula:

BSA = 0.024265 x (Height in cm)0.3964 x (Weight in kg)0.5378

Normal ranges for the parameters used:

  • CO = 4.0 - 8.0 L/min
  • SV = 60 - 100 mL/beat
  • HR = 60 - 100 beats/min
 

References

Ragosta M. Textbook of Clinical Hemodynamics. Elsevier; 2017.

Fagard R, Conway J. Measurement of cardiac output: Fick principle using catheterization. Eur Heart J. 1990; 11 Suppl I:1-5.

Carlsson et al. Cardiac output and cardiac index measured with cardiovascular magnetic resonance in healthy subjects, elite athletes and patients with congestive heart failure. J Cardiovasc Magn Reson. 2012; 14(1): 51.


Specialty: Cardiology

System: Circulatory

Abbreviation: CI

Article By: Denise Nedea

Published On: April 28, 2020

Last Checked: April 28, 2020

Next Review: April 28, 2025