Convert Inches of Water (60 °F) to Millimeters of Water
1 inch of water (60 °F) (inH₂O (60 °F)) equals 25.37461824 millimeters of water (mmH₂O).
1 inH₂O (60 °F) = 25.37461824 mmH₂O
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk inch of water (60 °F) to millimeter of water converter to paste a column from Excel.
How to Convert Inch of Water (60 °F) to Millimeter of Water
- 1 inH₂O (60 °F) = 25.37461824 mmH₂O
- 1 mmH₂O = 0.03940945989 inH₂O (60 °F)
- Example: convert 15 inH₂O (60 °F) to mmH₂O: 15 inH₂O (60 °F) = 15 × 25.37461824 mmH₂O = 380.6192737 mmH₂O
Reference conditions. inH₂O (60 °F): Water at 60 °F (15.6 °C), density ≈ 999.0 kg/m³, standard gravity. NIST value, 5 significant figures. mmH₂O: Conventional water column: ρ = 1000 kg/m³ and gₙ = 9.80665 m/s² (≈ water at 4 °C).
Formula
mmH₂O = inH₂O (60 °F) × 25.37461824374
Derivation from SI units:
- 1 inH₂O (60 °F) ≈ 999.0 kg/m³ × 9.80665 m/s² × 0.0254 m ≈ 248.84 Pa
- 1 mmH₂O = 1000 kg/m³ × 9.80665 m/s² × 0.001 m = 9.80665 Pa
- 1 inH₂O (60 °F) = 248.84 Pa ÷ 9.80665 Pa per mmH₂O = 25.37461824374 mmH₂O
One unit is a measured value, so the factor is approximate. Inch of Water (60 °F) definition: inch of water (60 °F); Millimeter of Water definition: millimeter of water.
Worked examples
- A reading of 0.5 inH₂O (60 °F) converts to 12.68730912 mmH₂O.
0.5 inH₂O (60 °F) × 25.37461824 = 12.68730912 mmH₂O - A value of 7 inH₂O (60 °F) is 177.6223277 mmH₂O.
7 inH₂O (60 °F) × 25.37461824 = 177.6223277 mmH₂O
Inch of Water (60 °F) to Millimeter of Water conversion table
| Inches of Water (60 °F) (inH₂O (60 °F)) | Millimeters of Water (mmH₂O) |
|---|---|
| 0.01 inH₂O (60 °F) | 0.2537461824 mmH₂O |
| 0.05 inH₂O (60 °F) | 1.268730912 mmH₂O |
| 0.1 inH₂O (60 °F) | 2.537461824 mmH₂O |
| 0.25 inH₂O (60 °F) | 6.343654561 mmH₂O |
| 0.5 inH₂O (60 °F) | 12.68730912 mmH₂O |
| 1 inH₂O (60 °F) | 25.37461824 mmH₂O |
| 2 inH₂O (60 °F) | 50.74923649 mmH₂O |
| 3 inH₂O (60 °F) | 76.12385473 mmH₂O |
| 5 inH₂O (60 °F) | 126.8730912 mmH₂O |
| 7 inH₂O (60 °F) | 177.6223277 mmH₂O |
| 10 inH₂O (60 °F) | 253.7461824 mmH₂O |
| 14 inH₂O (60 °F) | 355.2446554 mmH₂O |
| 20 inH₂O (60 °F) | 507.4923649 mmH₂O |
| 27.7 inH₂O (60 °F) | 702.8769254 mmH₂O |
Where it's used
Inches of Water (60 °F) are used for older US gas-industry and flow-meter references, while millimeters of water appear in fan static pressure and duct design in Asia and Europe. Both measure pressure, stress and differential pressure (force per unit area), so the conversion is a fixed factor.
Inch of Water (60 °F) to other pressure units
| Conversion | 1 inH₂O (60 °F) equals |
|---|---|
| inch of water (60 °F) to pascal | 248.84 Pa |
| inch of water (60 °F) to kilopascal | 0.24884 kPa |
| inch of water (60 °F) to megapascal | 0.00024884 MPa |
| inch of water (60 °F) to psi | 0.03609119066 psi |
| inch of water (60 °F) to bar | 0.0024884 bar |
| inch of water (60 °F) to millibar | 2.4884 mbar |
| inch of water (60 °F) to decibar | 0.024884 dbar |
| inch of water (60 °F) to torr | 1.866453491 Torr |
| inch of water (60 °F) to millimeter of mercury | 1.866453225 mmHg |
| inch of water (60 °F) to millimeter of water | 25.37461824 mmH₂O |
| inch of water (60 °F) to centimeter of water | 2.537461824 cmH₂O |
| inch of water (60 °F) to inch of water | 0.9990007183 inH₂O |
| inch of water (60 °F) to inch of mercury | 0.07348241045 inHg |
| inch of water (60 °F) to atmosphere | 0.002455859857 atm |
| inch of water (60 °F) to barye | 2488.4 Ba |
Frequently asked questions
How many millimeters of water are in 1 inch of water (60 °F)?
1 inH₂O (60 °F) = 25.37461824 mmH₂O.
How do I convert inches of water (60 °F) to millimeters of water?
Multiply the value in inH₂O (60 °F) by 25.37461824. For example, 15 inH₂O (60 °F) × 25.37461824 = 380.6192737 mmH₂O.
Is the inH₂O (60 °F) to mmH₂O conversion exact?
Not exactly. The inch of water (60 °F) is a measured value (Water at 60 °F (15.6 °C), density ≈ 999.0 kg/m³, standard gravity. NIST value, 5 significant figures.). Results are good to about 5 significant figures.
Sources
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "inch of water (60 °F)".
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "millimeter of water, conventional (mmH2O)".
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert Inches of Water (60 °F) to Millimeters of Water. Retrieved October 17, 2026, from https://scientificconverters.com/pressure/inch-of-water-60f-to-millimeter-of-water/
IEEE
Scientific Converters, "Convert Inches of Water (60 °F) to Millimeters of Water," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/pressure/inch-of-water-60f-to-millimeter-of-water/