# Cardiac Output and Cardiac Index Calculator

URL: https://speedycalculator.com/calculators/health/cardiac-output/
Last updated: 2026-10-25

> The cardiac output calculator multiplies heart rate by stroke volume to give litres of blood pumped per minute, and divides by body surface area for the cardiac index.

## Inputs

- Heart rate (bpm)
- Stroke volume (mL)
- Height (cm, m, mm, in, ft)
- Weight (kg, lb, g, oz, st)

## Results

- Cardiac output
- Body surface area
- Cardiac index

## Formula

```
CO = HR × SV ÷ 1000 (L/min)
CI = CO ÷ BSA
```

## Explanation

Cardiac output describes how well the heart meets the body’s demand for blood flow.

### How to use the Cardiac Output and Cardiac Index Calculator

- **Heart rate**
- **Stroke volume**
- **Height**
- **Weight**

Results update as you type, and every field accepts the units shown in its menu.

### How it works

Multiply beats per minute by the volume ejected per beat. BSA comes from the Mosteller formula.

### Inputs explained

FieldWhat to enterHeart rateIn bpmStroke volumeIn mLHeightUnits: cm, m, mm, in, ftWeightUnits: kg, lb, g, oz, st

### What each result means

- **Cardiac output** = [Heart rate] × [Stroke volume] ÷ 1000
- **Body surface area** = sqrt([Height]×[Weight]÷3600)
- **Cardiac index** = [Cardiac output] ÷ [Body surface area]

### Example values

How the main result changes when **Heart rate** changes and everything else stays at the example values above:

Heart rate (bpm)Cardiac output (L/min)362.52543.78725.04906.31087.5614410.08
*Health note: this calculator is for education and screening only and is not a diagnosis or treatment advice. Discuss your results with a qualified clinician.*

## Worked example

Inputs — Heart rate: 72 bpm; Stroke volume: 70 mL; Height: 175 cm; Weight: 75 kg.

Results — **Cardiac output = 5.04 L/min**; Body surface area = 1.91 m²; Cardiac index = 2.64 L/min/m².

## FAQ

**What is a normal cardiac output?**
About 4–8 L/min at rest in adults.

**What is a normal cardiac index?**
Roughly 2.5–4.0 L/min/m².

**What formula does the Cardiac Output and Cardiac Index Calculator use?**
CO = HR × SV ÷ 1000 (L/min).