mmH2O to inHg Converter
Pressure · unit-converter
Convert mmH2O to inHg 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 inHg
Inches of mercury (inHg) is used in aviation altimetry and vacuum readings in some US contexts.
How to convert millimeter of water (mmh2o, 4 °c) to inch of mercury (inhg)
1 mmh2o equals 0.0028959025199610765 inhg in this tool (via pascal):
1 mmh2o = (9.80665 Pa ÷ 3386.38815789 Pa) inhg = 0.0028959025199610765 inhg
Each mmh2o carries 9.80665 Pa and each inhg 3386.38815789 Pa, so one mmh2o equals 9.80665 ÷ 3386.38815789 inhg.
Let p(mmh2o) be pressure in mmH2O (mmh2o), and p(inhg) in inHg (inhg). Then:
p(inhg) = p(mmh2o) × (9.80665 / 3386.38815789)
Equivalently, divide by how many mmh2o fit into one inhg (Pa per inhg divided by Pa per mmh2o):
p(inhg) = p(mmh2o) ÷ 345.31549080368933
Examples
Example #1: Convert 1 mmh2o to inhg
1 mmh2o = 1 mmh2o × (9.80665/3386.38815789) inhg = 0.0028959025 inhg
1 mmh2o = 1 mmh2o ÷ 345.31549080368933 = 0.0028959025 inhg
1 mmh2o × (9.80665/3,386.38815789) = 0.002896 inhg
Example #2: Convert 10 mmh2o to inhg
10 mmh2o = 10 mmh2o × (9.80665/3386.38815789) inhg = 0.0289590252 inhg
10 mmh2o = 10 mmh2o ÷ 345.31549080368933 = 0.0289590252 inhg
10 mmh2o × (9.80665/3,386.38815789) = 0.028959 inhg
Summary
To convert mmH2O to inHg, multiply the value in mmh2o by (9.80665 Pa per mmh2o) / (3386.38815789 Pa per inhg). Equivalently: value_inhg = value_mmh2o × (9.80665 / 3386.38815789). Numerically, 1 mmh2o equals 0.0028959025199610765 inhg.
Relationship context
Both mmH2O and inHg are converted by fixed multiples of the pascal. Multiplying by (Pa per mmh2o) ÷ (Pa per inhg) 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) | inHg (inhg) |
|---|---|
| 0.1 | 0.0002895903 |
| 1 | 0.0028959025 |
| 2 | 0.005791805 |
| 3 | 0.0086877076 |
| 4 | 0.0115836101 |
| 5 | 0.0144795126 |
| 6 | 0.0173754151 |
| 7 | 0.0202713176 |
| 8 | 0.0231672202 |
| 9 | 0.0260631227 |
| mmH2O (mmh2o) | inHg (inhg) |
|---|---|
| 10 | 0.0289590252 |
| 20 | 0.0579180504 |
| 30 | 0.0868770756 |
| 40 | 0.1158361008 |
| 50 | 0.144795126 |
| 60 | 0.1737541512 |
| 70 | 0.2027131764 |
| 80 | 0.2316722016 |
| 90 | 0.2606312268 |
| 100 | 0.289590252 |