Convert Kilopascals to Inches of Water

Convert Kilopascals (kPa) to Inches of Water (inH₂O) instantly and accurately.

Kilopascals (kPa)
Inches of Water (inH₂O)

Conversion Formula

inH₂O = kPa × 4.01463076

About Kilopascals

A kilopascal (kPa) = 1,000 Pa - the practical everyday SI pressure unit for moderate pressures. Car tyre inflation: 200-250 kPa (29-36 psi); truck tyres 550-830 kPa. Blood pressure in SI countries: 16/10.7 kPa (= 120/80 mmHg). Systolic blood pressure 16 kPa. Carbonated beverages are packaged at 200-500 kPa CO₂. Medical oxygen cylinders at 15,000 kPa; scuba cylinders 200-300 bar = 20,000-30,000 kPa. 1 kPa = 1,000 Pa = 0.01 bar = 0.145 psi.

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

Kilopascals (kPa)Inches of Water (inH₂O)
1 kPa4.01463 inH₂O
2 kPa8.02926 inH₂O
5 kPa20.0732 inH₂O
10 kPa40.1463 inH₂O
25 kPa100.366 inH₂O
50 kPa200.732 inH₂O
100 kPa401.463 inH₂O

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