Convert Millipascals to Inches of Water
Convert Millipascals (mPa) to Inches of Water (inH₂O) instantly and accurately.
Conversion Formula
inH₂O = mPa × 4.014630760e-6
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.
About Inches of Water
One inch of water column (inH₂O or in WC) = pressure from 1 inch of fresh water at standard gravity ≈ 249.09 Pa. The standard unit for low-pressure measurement in US HVAC and plumbing: ductwork static pressure, fan performance, filter ratings, and gas appliance manifold pressures are all specified in inches WC. Household natural gas supply pressure is typically 7 in WC (0.25 psi). Blower door tests for building air-tightness use 50 Pa ≈ 0.2 in WC test pressure. 1 inH₂O = 249.089 Pa.
Quick Reference Table
| Millipascals (mPa) | Inches of Water (inH₂O) |
|---|---|
| 1 mPa | 4.015 × 10-6 inH₂O |
| 2 mPa | 8.029 × 10-6 inH₂O |
| 5 mPa | 2.007 × 10-5 inH₂O |
| 10 mPa | 4.015 × 10-5 inH₂O |
| 25 mPa | 0.000100366 inH₂O |
| 50 mPa | 0.000200732 inH₂O |
| 100 mPa | 0.000401463 inH₂O |