Convert Millimeters of Water to Megapascals
Convert Millimeters of Water (mmH₂O) to Megapascals (MPa) instantly and accurately.
Conversion Formula
MPa = mmH₂O × 9.806650000e-6
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.
About Megapascals
A megapascal (MPa) = 10⁶ Pa = 10 bar - standard unit for mechanical stress, material strength, and high-pressure engineering. Structural material yield strengths: mild steel 250-550 MPa; high-strength steel to 2,000 MPa; carbon fibre composites 1,500-7,000 MPa tensile. Hydraulic press pressures 50-200 MPa. Mariana Trench floor ~110 MPa. Concrete compressive strength: 25-40 MPa (normal); up to 150 MPa (high-performance). Water-jet cutting: 200-600 MPa. Elastic moduli in FEM analysis are in MPa or GPa. 1 MPa = 10⁶ Pa = 145.0 psi.
Quick Reference Table
| Millimeters of Water (mmH₂O) | Megapascals (MPa) |
|---|---|
| 1 mmH₂O | 9.807 × 10-6 MPa |
| 2 mmH₂O | 1.961 × 10-5 MPa |
| 5 mmH₂O | 4.903 × 10-5 MPa |
| 10 mmH₂O | 9.807 × 10-5 MPa |
| 25 mmH₂O | 0.000245166 MPa |
| 50 mmH₂O | 0.000490332 MPa |
| 100 mmH₂O | 0.000980665 MPa |