mmH2O to Hectopascal Converter
Pressure · unit-converter
Convert mmH2O to Hectopascal with a fixed input and output unit, step-by-step formula line, and reference tables. All calculations bridge through pascal with fixed definitions (standard atmosphere = 101,325 Pa; torr and mmHg = atm/760; plus industrial/manometer units like kgf/cm², inHg, inH2O, and mmH2O).
About mmH2O
Millimeters of water column (mmH2O) is used for very low differential pressure in instrumentation and ventilation.
About Hectopascal
The hectopascal (hPa) equals 100 Pa. Meteorologists use hPa for surface charts; 1 hPa equals 1 millibar.
How to convert millimeter of water (mmh2o, 4 °c) to hectopascal (hpa)
1 mmh2o equals 0.0980665 hectopascal in this tool (via pascal):
1 mmh2o = (9.80665 Pa ÷ 100 Pa) hpa = 0.0980665 hpa
Each mmh2o carries 9.80665 Pa and each hectopascal 100 Pa, so one mmh2o equals 9.80665 ÷ 100 hpa.
Let p(mmh2o) be pressure in mmH2O (mmh2o), and p(hpa) in Hectopascal (hpa). Then:
p(hpa) = p(mmh2o) × (9.80665 / 100)
Equivalently, divide by how many mmh2o fit into one hpa (Pa per hpa divided by Pa per mmh2o):
p(hpa) = p(mmh2o) ÷ 10.197162129779283
Examples
Example #1: Convert 1 mmh2o to hectopascal
1 mmh2o = 1 mmh2o × (9.80665/100) hpa = 0.0980665 hpa
1 mmh2o = 1 mmh2o ÷ 10.197162129779283 = 0.0980665 hpa
1 mmh2o × (9.80665/100) = 0.098067 hpa
Example #2: Convert 10 mmh2o to hectopascal
10 mmh2o = 10 mmh2o × (9.80665/100) hpa = 0.980665 hpa
10 mmh2o = 10 mmh2o ÷ 10.197162129779283 = 0.980665 hpa
10 mmh2o × (9.80665/100) = 0.980665 hpa
Summary
To convert mmH2O to Hectopascal, multiply the value in mmh2o by (9.80665 Pa per mmh2o) / (100 Pa per hpa). Equivalently: value_hpa = value_mmh2o × (9.80665 / 100). Numerically, 1 mmh2o equals 0.0980665 hpa.
Relationship context
Both mmH2O and Hectopascal are converted by fixed multiples of the pascal. Multiplying by (Pa per mmh2o) ÷ (Pa per hpa) gives the same result as passing through pascal, keeping bar, atm, PSI, kPa, hPa, torr, and mmHg consistent on the hub.
Conversion tables
| mmH2O (mmh2o) | Hectopascal (hpa) |
|---|---|
| 0.1 | 0.00980665 |
| 1 | 0.0980665 |
| 2 | 0.196133 |
| 3 | 0.2941995 |
| 4 | 0.392266 |
| 5 | 0.4903325 |
| 6 | 0.588399 |
| 7 | 0.6864655 |
| 8 | 0.784532 |
| 9 | 0.8825985 |
| mmH2O (mmh2o) | Hectopascal (hpa) |
|---|---|
| 10 | 0.980665 |
| 20 | 1.96133 |
| 30 | 2.941995 |
| 40 | 3.92266 |
| 50 | 4.903325 |
| 60 | 5.88399 |
| 70 | 6.864655 |
| 80 | 7.84532 |
| 90 | 8.825985 |
| 100 | 9.80665 |