Hectopascal to inH2O Converter
Pressure · unit-converter
Convert Hectopascal to inH2O 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 Hectopascal
The hectopascal (hPa) equals 100 Pa. Meteorologists use hPa for surface charts; 1 hPa equals 1 millibar.
About inH2O
Inches of water column (inH2O) is common in low-pressure HVAC and duct static-pressure measurements.
How to convert hectopascal (hpa) to inch of water (inh2o, 4 °c)
1 hectopascal equals 0.4014630759755623 inh2o in this tool (via pascal):
1 hpa = (100 Pa ÷ 249.08891 Pa) inh2o = 0.4014630759755623 inh2o
Each hectopascal carries 100 Pa and each inh2o 249.08891 Pa, so one hpa equals 100 ÷ 249.08891 inh2o.
Let p(hpa) be pressure in Hectopascal (hpa), and p(inh2o) in inH2O (inh2o). Then:
p(inh2o) = p(hpa) × (100 / 249.08891)
Equivalently, divide by how many hpa fit into one inh2o (Pa per inh2o divided by Pa per hpa):
p(inh2o) = p(hpa) ÷ 2.4908891
Examples
Example #1: Convert 1 hpa to inh2o
1 hpa = 1 hpa × (100/249.08891) inh2o = 0.401463076 inh2o
1 hpa = 1 hpa ÷ 2.4908891 = 0.401463076 inh2o
1 hpa × (100/249.08891) = 0.401463 inh2o
Example #2: Convert 10 hpa to inh2o
10 hpa = 10 hpa × (100/249.08891) inh2o = 4.0146307598 inh2o
10 hpa = 10 hpa ÷ 2.4908891 = 4.0146307598 inh2o
10 hpa × (100/249.08891) = 4.014631 inh2o
Summary
To convert Hectopascal to inH2O, multiply the value in hpa by (100 Pa per hpa) / (249.08891 Pa per inh2o). Equivalently: value_inh2o = value_hpa × (100 / 249.08891). Numerically, 1 hpa equals 0.4014630759755623 inh2o.
Relationship context
Both Hectopascal and inH2O are converted by fixed multiples of the pascal. Multiplying by (Pa per hpa) ÷ (Pa per inh2o) gives the same result as passing through pascal, keeping bar, atm, PSI, kPa, hPa, torr, and mmHg consistent on the hub.
Conversion tables
| Hectopascal (hpa) | inH2O (inh2o) |
|---|---|
| 0.1 | 0.0401463076 |
| 1 | 0.401463076 |
| 2 | 0.802926152 |
| 3 | 1.2043892279 |
| 4 | 1.6058523039 |
| 5 | 2.0073153799 |
| 6 | 2.4087784558 |
| 7 | 2.8102415318 |
| 8 | 3.2117046078 |
| 9 | 3.6131676838 |
| Hectopascal (hpa) | inH2O (inh2o) |
|---|---|
| 10 | 4.0146307598 |
| 20 | 8.0292615195 |
| 30 | 12.0438922793 |
| 40 | 16.058523039 |
| 50 | 20.0731537988 |
| 60 | 24.0877845585 |
| 70 | 28.1024153183 |
| 80 | 32.117046078 |
| 90 | 36.1316768378 |
| 100 | 40.1463075976 |