Convert Inches of Water to Pascals
Convert Inches of Water (inH₂O) to Pascals (Pa) instantly and accurately.
Conversion Formula
Pa = inH₂O × 249.08891
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.
About Pascals
The pascal (Pa) is the SI unit of pressure - 1 N/m², named after Blaise Pascal (1623-1662). Standard sea-level atmosphere ≈ 101,325 Pa. One pascal is very small: roughly the pressure of a single banknote lying flat. Pascal is simultaneously the SI unit for mechanical stress and elastic modulus: structural steel Young's modulus ~200 GPa; rubber shear modulus ~0.5 MPa. Used universally in fluid mechanics, acoustics, atmospheric science, and materials engineering. 1 Pa = 1 N/m².
Quick Reference Table
| Inches of Water (inH₂O) | Pascals (Pa) |
|---|---|
| 1 inH₂O | 249.089 Pa |
| 2 inH₂O | 498.178 Pa |
| 5 inH₂O | 1245.44 Pa |
| 10 inH₂O | 2490.89 Pa |
| 25 inH₂O | 6227.22 Pa |
| 50 inH₂O | 12454.4 Pa |
| 100 inH₂O | 24908.9 Pa |