Convert Standard Atmospheres to Centimeters of Water
Convert Standard Atmospheres (atm) to Centimeters of Water (cmH₂O) instantly and accurately.
Conversion Formula
cmH₂O = atm × 1033.227453
About Standard Atmospheres
The standard atmosphere (atm) = exactly 101,325 Pa - defined by the 10th CGPM (1954) as the reference air pressure at sea level. Used to define STP (0°C and 1 atm) for gas law and thermochemistry. Chemical equilibrium constants (Kp), Henry's law solubility, and thermodynamic tables are tabulated at 1 atm. ISA aviation standard: sea-level 1 atm / 15°C, pressure halving every ~5.5 km. Diving physics: +1 atm per 10 m depth (fresh water) so 30 m = 4 atm absolute. Diamond formation in Earth's mantle: ~50,000 atm. 1 atm = 101,325 Pa.
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.
Quick Reference Table
| Standard Atmospheres (atm) | Centimeters of Water (cmH₂O) |
|---|---|
| 1 atm | 1033.23 cmH₂O |
| 2 atm | 2066.45 cmH₂O |
| 5 atm | 5166.14 cmH₂O |
| 10 atm | 10332.3 cmH₂O |
| 25 atm | 25830.7 cmH₂O |
| 50 atm | 51661.4 cmH₂O |
| 100 atm | 103323 cmH₂O |