Convert Centimeters of Water to Inches of Mercury
Convert Centimeters of Water (cmH₂O) to Inches of Mercury (inHg) instantly and accurately.
Conversion Formula
inHg = cmH₂O × 0.02895902107
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 Inches of Mercury
One inch of mercury (inHg) ≈ 3,386 Pa - the primary barometric pressure unit in US aviation and meteorology. ASOS weather stations, METARs, and altimeter settings in the US report in inHg. Standard sea-level pressure is 29.92 inHg. Altimeters are set to local QNH in inHg to maintain altitude reference. US barometers for home weather stations display inHg. Typical pressure range: 28.5-31.0 inHg in continental weather systems. Record low: ~25.70 inHg (Typhoon Tip, 1979). 1 inHg = 3,386.39 Pa.
Quick Reference Table
| Centimeters of Water (cmH₂O) | Inches of Mercury (inHg) |
|---|---|
| 1 cmH₂O | 0.028959 inHg |
| 2 cmH₂O | 0.057918 inHg |
| 5 cmH₂O | 0.144795 inHg |
| 10 cmH₂O | 0.28959 inHg |
| 25 cmH₂O | 0.723976 inHg |
| 50 cmH₂O | 1.44795 inHg |
| 100 cmH₂O | 2.8959 inHg |