Convert Centimeters of Water to Feet of Water
Convert Centimeters of Water (cmH₂O) to Feet of Water (ftH₂O) instantly and accurately.
Conversion Formula
ftH₂O = cmH₂O × 0.03280839895
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 Feet of Water
One foot of water column (ftH₂O) ≈ 2,989 Pa - the US customary equivalent of cmH₂O used in civil and hydraulic engineering. Municipal water supply systems are designed for 40-80 psi head ≈ 92-184 ft; fire suppression sprinkler systems require minimum 7 psi ≈ 16 ft. Well pump specifications, sump pump head ratings, irrigation mainline pressure, and drainage calculations all use feet of head. 1 ft of water = 12 in WC = 0.4335 psi ≈ 2,989 Pa.
Quick Reference Table
| Centimeters of Water (cmH₂O) | Feet of Water (ftH₂O) |
|---|---|
| 1 cmH₂O | 0.0328084 ftH₂O |
| 2 cmH₂O | 0.0656168 ftH₂O |
| 5 cmH₂O | 0.164042 ftH₂O |
| 10 cmH₂O | 0.328084 ftH₂O |
| 25 cmH₂O | 0.82021 ftH₂O |
| 50 cmH₂O | 1.64042 ftH₂O |
| 100 cmH₂O | 3.28084 ftH₂O |