Kilopascals to Inches Of Water (kPa to inH₂O)
1 kilopascal equals 4.01463076 inches of water (rounded).
How to convert kilopascals to inches of water
To convert kilopascals to inches of water, multiply the number of kilopascals by 4.01463076. The factor is rounded to 10 significant digits. To go the other way, multiply inches of water by 0.24908891.
inches of water = kilopascals × 4.01463076
Example: 10 kilopascals = 40.1463076 inches of water.
About these units
Kilopascal (kPa)
1,000 pascals. Used for tire pressures, weather reports in many countries and engineering.
Kilopascal is the form of the pascal that most people actually use. The pascal itself is very small, so outside meteorology the kilopascal became the common choice in most fields, and it equals one centibar. Medical elastography reports tissue stiffness in kPa, and Canada reports atmospheric pressure in kPa rather than hectopascals.
A standard atmosphere is 101.325 kPa. In 1982 IUPAC recommended a different reference for chemistry, a standard pressure of exactly 100 kPa, which split the older convention of 1 atm into two competing standards.
Blood pressure shows how the units line up. One mmHg is 0.13332 kPa, and a normal reading is below about 16.0 kPa systolic and 10.7 kPa diastolic, the same thing as the familiar 120 over 80 in millimeters of mercury.
1 kilopascal = 1,000 pascals (exactly).
Sources: Wikipedia: Pascal (unit); Wikipedia: Standard atmosphere (unit); Wikipedia: Millimetre of mercury
Inch Of Water (inH₂O)
About 249.089 pascals (the conventional value, 25.4 mm × 9.80665 Pa). Used for air pressure in HVAC and gas appliances.
Building services and gas fitting rely on this unit. Manometers filled with water read small differences in air or gas pressure, and in North America the result is stated in inches of water column. Natural gas supplied to appliances is typically 6 to 7 inches WC, and HVAC technicians use it for pressure across coils, filters and ducts. A pipe organ's wind pressure is quoted the same way.
Which water is meant matters a little. Wikipedia gives about 249.082 Pa for water at 4 degrees Celsius, equal to 39.2 degrees Fahrenheit, and also the conventional 249.08891 Pa, which is 25.4 mm times 9.80665 and is the figure used here. NIST lists 249.082 Pa at 39.2 degrees Fahrenheit and 248.84 Pa at 60 degrees Fahrenheit, and some industry standards use 60 or 68 degrees Fahrenheit. About 27.7 inches of water equal 1 psi.
1 inch of water = 249.08891 pascals (exactly).
Sources: Wikipedia: Inch of water; NIST SP 811, Appendix B.8
Related conversions
- Inches of water to kilopascals (reverse)
- Kilopascals to pascals
- Kilopascals to bars
- Kilopascals to standard atmospheres
- Kilopascals to PSI
- Kilopascals to hectopascals
- Kilopascals to megapascals
- Kilopascals to millibars
- Kilopascals to torr
- Kilopascals to millimeters of mercury
- Kilopascals to inches of mercury
- Kilopascals to gigapascals
- Kilopascals to kilopounds per square inch
- Pascals to inches of water
- Bars to inches of water
- Standard atmospheres to inches of water
- PSI to inches of water
See all pressure units.