Convert Centimeters of Mercury to Inches of Water
Convert Centimeters of Mercury (cmHg) to Inches of Water (inH₂O) instantly and accurately.
Conversion Formula
inH₂O = cmHg × 5.352401575
About Centimeters of Mercury
One centimetre of mercury (cmHg) = 10 mmHg ≈ 1,333.22 Pa. Historical medical and physiological literature used cmHg for intracardiac and intravascular pressures before mmHg became universal. Left ventricular systolic pressure ~12 cmHg; pulmonary artery systolic 2-3 cmHg. Some older European cardiological textbooks and pre-1970s surgical literature report pressures in cmHg. Central venous pressure, cerebral perfusion pressure, and intra-abdominal pressure are occasionally cited in cmHg in legacy datasets. 1 cmHg = 1,333.22 Pa.
About Inches of Water
One inch of water column (inH₂O or in WC) = pressure from 1 inch of fresh water at standard gravity ≈ 249.09 Pa. The standard unit for low-pressure measurement in US HVAC and plumbing: ductwork static pressure, fan performance, filter ratings, and gas appliance manifold pressures are all specified in inches WC. Household natural gas supply pressure is typically 7 in WC (0.25 psi). Blower door tests for building air-tightness use 50 Pa ≈ 0.2 in WC test pressure. 1 inH₂O = 249.089 Pa.
Quick Reference Table
| Centimeters of Mercury (cmHg) | Inches of Water (inH₂O) |
|---|---|
| 1 cmHg | 5.3524 inH₂O |
| 2 cmHg | 10.7048 inH₂O |
| 5 cmHg | 26.762 inH₂O |
| 10 cmHg | 53.524 inH₂O |
| 25 cmHg | 133.81 inH₂O |
| 50 cmHg | 267.62 inH₂O |
| 100 cmHg | 535.24 inH₂O |