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
| Field | What to enter |
|---|---|
| Heart rate | In bpm |
| Stroke volume | In mL |
| Height | Units: cm, m, mm, in, ft |
| Weight | Units: 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) |
|---|---|
| 36 | 2.52 |
| 54 | 3.78 |
| 72 | 5.04 |
| 90 | 6.3 |
| 108 | 7.56 |
| 144 | 10.08 |
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.
Formula
CO = HR × SV ÷ 1000 (L/min)CI = CO ÷ BSAWorked 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.
Frequently asked questions
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).