Convert Millimeters of Water to Millipascals
Convert Millimeters of Water (mmH₂O) to Millipascals (mPa) instantly and accurately.
Conversion Formula
mPa = mmH₂O × 9806.65
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 Millipascals
A millipascal (mPa) is 10⁻³ Pa. It appears primarily in rheology as the millipascal-second (mPa·s = centipoise) for dynamic viscosity: water at 20°C is 1.002 mPa·s; olive oil ~80 mPa·s; honey 2,000-10,000 mPa·s. Food technology, polymer processing, pharmaceutical formulation, and inkjet printing all specify flow behaviour in mPa·s. Partial pressures of trace atmospheric gases and ultra-high-vacuum leak rates measured by residual gas analysers are also expressed in millipascals. 1 mPa = 10⁻³ Pa.
Quick Reference Table
| Millimeters of Water (mmH₂O) | Millipascals (mPa) |
|---|---|
| 1 mmH₂O | 9806.65 mPa |
| 2 mmH₂O | 19613.3 mPa |
| 5 mmH₂O | 49033.3 mPa |
| 10 mmH₂O | 98066.5 mPa |
| 25 mmH₂O | 245166 mPa |
| 50 mmH₂O | 490333 mPa |
| 100 mmH₂O | 980665 mPa |