Convert Centimeters of Water to Hectopascals
Convert Centimeters of Water (cmH₂O) to Hectopascals (hPa) instantly and accurately.
Conversion Formula
hPa = cmH₂O × 0.980665
About Centimeters of Water
One centimetre of water column (cmH₂O) ≈ 98.07 Pa - the clinical pressure unit for respiratory and intravascular measurements. Mechanical ventilator settings are in cmH₂O: peak inspiratory pressure (PIP) 15-30 cmH₂O; PEEP 5-15 cmH₂O; plateau pressure should stay below 30 cmH₂O to avoid lung injury. Lumbar puncture CSF opening pressure is normally 8-20 cmH₂O. CPAP/BiPAP therapy for sleep apnea: 4-20 cmH₂O. Central venous pressure is also reported in cmH₂O. 1 cmH₂O = 98.0665 Pa.
About Hectopascals
A hectopascal (hPa) = 100 Pa = 1 mbar - the WMO-official SI-compatible meteorological pressure unit since 1986, replacing millibar with no numerical change. All modern surface observations (METAR, SYNOP), digital barometers, aviation weather, and weather apps report in hPa. QNH altimeter settings outside North America are in hPa. ICAO standard sea-level pressure is 1013.25 hPa. Continental high-pressure record exceeds 1084 hPa; Typhoon Tip (1979) holds the low record at ~870 hPa. 1 hPa = 100 Pa.
Quick Reference Table
| Centimeters of Water (cmH₂O) | Hectopascals (hPa) |
|---|---|
| 1 cmH₂O | 0.980665 hPa |
| 2 cmH₂O | 1.96133 hPa |
| 5 cmH₂O | 4.90332 hPa |
| 10 cmH₂O | 9.80665 hPa |
| 25 cmH₂O | 24.5166 hPa |
| 50 cmH₂O | 49.0333 hPa |
| 100 cmH₂O | 98.0665 hPa |