Convert Bar to Millimeters of Water
1 bar equals 10197.16213 millimeters of water (mmH₂O).
1 bar = 10197.16213 mmH₂O
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk bar to millimeter of water converter to paste a column from Excel.
How to Convert Bar to Millimeter of Water
- 1 bar = 10197.16213 mmH₂O
- 1 mmH₂O = 0.0000980665 bar
- Example: convert 15 bar to mmH₂O: 15 bar = 15 × 10197.16213 mmH₂O = 152957.4319 mmH₂O
Reference conditions. mmH₂O: Conventional water column: ρ = 1000 kg/m³ and gₙ = 9.80665 m/s² (≈ water at 4 °C).
Formula
mmH₂O = bar × 10197.16212978
Derivation from SI units:
- 1 bar = 10⁵ Pa (exact, by definition)
- 1 mmH₂O = 1000 kg/m³ × 9.80665 m/s² × 0.001 m = 9.80665 Pa
- 1 bar = 100000 Pa ÷ 9.80665 Pa per mmH₂O = 10197.16212978 mmH₂O
Both units are defined exactly, so the factor is exact. Bar definition: bar; Millimeter of Water definition: millimeter of water.
Worked examples
- A reading of 2 bar converts to 20394.32426 mmH₂O.
2 bar × 10197.16213 = 20394.32426 mmH₂O - A value of 10 bar is 101971.6213 mmH₂O.
10 bar × 10197.16213 = 101971.6213 mmH₂O
Bar to Millimeter of Water conversion table
| Bar | Millimeters of Water (mmH₂O) |
|---|---|
| 0.01 bar | 101.9716213 mmH₂O |
| 0.05 bar | 509.8581065 mmH₂O |
| 0.1 bar | 1019.716213 mmH₂O |
| 0.25 bar | 2549.290532 mmH₂O |
| 0.5 bar | 5098.581065 mmH₂O |
| 1 bar | 10197.16213 mmH₂O |
| 1.01325 bar | 10332.27453 mmH₂O |
| 1.5 bar | 15295.74319 mmH₂O |
| 2 bar | 20394.32426 mmH₂O |
| 2.5 bar | 25492.90532 mmH₂O |
| 3 bar | 30591.48639 mmH₂O |
| 4 bar | 40788.64852 mmH₂O |
| 5 bar | 50985.81065 mmH₂O |
| 6 bar | 61182.97278 mmH₂O |
| 7 bar | 71380.13491 mmH₂O |
| 8 bar | 81577.29704 mmH₂O |
| 10 bar | 101971.6213 mmH₂O |
| 12 bar | 122365.9456 mmH₂O |
| 16 bar | 163154.5941 mmH₂O |
| 20 bar | 203943.2426 mmH₂O |
| 25 bar | 254929.0532 mmH₂O |
| 40 bar | 407886.4852 mmH₂O |
| 100 bar | 1019716.213 mmH₂O |
| 200 bar | 2039432.426 mmH₂O |
| 300 bar | 3059148.639 mmH₂O |
Where it's used
Bar are used for compressed air and pneumatics (6–8 bar), 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.
Bar to other pressure units
| Conversion | 1 bar equals |
|---|---|
| bar to pascal | 100000 Pa |
| bar to kilopascal | 100 kPa |
| bar to megapascal | 0.1 MPa |
| bar to psi | 14.50377377 psi |
| bar to millibar | 1000 mbar |
| bar to decibar | 10 dbar |
| bar to torr | 750.0616827 Torr |
| bar to millimeter of mercury | 750.0615758 mmHg |
| bar to millimeter of water | 10197.16213 mmH₂O |
| bar to centimeter of water | 1019.716213 cmH₂O |
| bar to inch of water | 401.463076 inH₂O |
| bar to inch of water (60 °F) | 401.864652 inH₂O (60 °F) |
| bar to inch of mercury | 29.5299833 inHg |
| bar to atmosphere | 0.9869232667 atm |
| bar to barye | 1000000 Ba |
Frequently asked questions
How many millimeters of water are in 1 bar?
1 bar = 10197.16213 mmH₂O.
How do I convert bar to millimeters of water?
Multiply the value in bar by 10197.16213. For example, 15 bar × 10197.16213 = 152957.4319 mmH₂O.
Is the bar to mmH₂O conversion exact?
Yes. Both units are defined exactly, so the ratio is exact; its decimal form does not terminate and is shown here to 10 significant figures (more with the precision selector).
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, "bar".
- 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 Bar to Millimeters of Water. Retrieved October 17, 2026, from https://scientificconverters.com/pressure/bar-to-millimeter-of-water/
IEEE
Scientific Converters, "Convert Bar to Millimeters of Water," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/pressure/bar-to-millimeter-of-water/