Blood gases & acid-base

pCO2 unit converter

Partial pressure of carbon dioxide in blood (blood gas)

Also known as: PaCO2, Partial pressure of carbon dioxide, Carbon dioxide tension, Arterial CO2 tension, Kohlendioxidpartialdruck, Pression partielle en CO2

Converter

Enter a value in any unit and all other units fill in.

kPa mmHg

Worked example

40 mmHg (middle of the reference range) = 5.33 kPa

Conversion formulas

kPa	kPa = mmHg × 0.1333	mmHg = kPa × 7.501

Reference range

Unit	Adults
kPa	5.066 – 5.599
mmHg	38 – 42

Source: MedlinePlus (NLM): Blood gases · Last reviewed: 2026-10-14

Note from the source: PaCO2 38-42 mmHg (5.1-5.6 kPa), arterial blood at sea level (MedlinePlus)

Frequently asked questions

How do I convert pCO2 from mmHg to kPa?

kPa = mmHg × 0.1333. In the other direction: mmHg = kPa × 7.501.

What is the reference range of pCO2?

For adults the range is 38 – 42 mmHg (MedlinePlus (NLM): Blood gases). Reference ranges differ between laboratories and partly by sex and age; use the range printed on your lab report.

Which units are used for pCO2?

Common units are kPa, mmHg.