Convert Bars to Millimeters of Water
Convert Bars (bar) to Millimeters of Water (mmH₂O) instantly and accurately.
Conversion Formula
mmH₂O = bar × 10197.16213
About Bars
A bar = exactly 100,000 Pa ≈ 0.987 atm - the world standard for industrial pressure outside North America. Hydraulic systems, pneumatic equipment, gas cylinders, dive computers, and tyre gauges in Europe and Asia use bar. Scuba diving: +1 bar per 10 m depth; at 40 m recreational limit = 5 bar absolute. European tyre pressure labels show bar alongside kPa. Industrial processes: steam at 10-50 bar; high-pressure reactors 100-300 bar; water-jet cutting 1,000-4,000 bar. 1 bar = 100,000 Pa = 14.504 psi.
About Millimeters of Water
One millimetre of water column (mmH₂O) = pressure from 1 mm of fresh water at standard gravity = exactly 9.80665 Pa. Preferred for very low differential pressures in HVAC: ductwork static pressures, fan curves, filter resistance, and building pressurisation are in mm WC. Gas valve operating pressures are typically 0.5-3 mm WC; clean-room cascade differentials 12-25 mm WC. A domestic gas hob manifold operates at ~20 mm WC on natural gas. Also used in spirometer calibration and hospital oxygen delivery systems. 1 mmH₂O = 9.80665 Pa.
Quick Reference Table
| Bars (bar) | Millimeters of Water (mmH₂O) |
|---|---|
| 1 bar | 10197.2 mmH₂O |
| 2 bar | 20394.3 mmH₂O |
| 5 bar | 50985.8 mmH₂O |
| 10 bar | 101972 mmH₂O |
| 25 bar | 254929 mmH₂O |
| 50 bar | 509858 mmH₂O |
| 100 bar | 1019720 mmH₂O |