Atmosphere to inH2O Converter
Pressure · unit-converter
Convert Atmosphere 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 Atmosphere
The standard atmosphere (atm) is defined as exactly 101,325 Pa. It links legacy chemistry and physics problems to SI.
About inH2O
Inches of water column (inH2O) is common in low-pressure HVAC and duct static-pressure measurements.
How to convert atmosphere to inch of water (inh2o, 4 °c)
1 atmosphere equals 406.7824617322385 inh2o in this tool (via pascal):
1 atm = (101325 Pa ÷ 249.08891 Pa) inh2o = 406.7824617322385 inh2o
Each atmosphere carries 101325 Pa and each inh2o 249.08891 Pa, so one atm equals 101325 ÷ 249.08891 inh2o.
Let p(atm) be pressure in Atmosphere (atm), and p(inh2o) in inH2O (inh2o). Then:
p(inh2o) = p(atm) × (101325 / 249.08891)
Equivalently, divide by how many atm fit into one inh2o (Pa per inh2o divided by Pa per atm):
p(inh2o) = p(atm) ÷ 0.0024583164075993092
Examples
Example #1: Convert 1 atm to inh2o
1 atm = 1 atm × (101325/249.08891) inh2o = 406.782461732 inh2o
1 atm = 1 atm ÷ 0.0024583164075993092 = 406.782461732 inh2o
1 atm × (101,325/249.08891) = 406.782462 inh2o
Example #2: Convert 10 atm to inh2o
10 atm = 10 atm × (101325/249.08891) inh2o = 4067.82461732 inh2o
10 atm = 10 atm ÷ 0.0024583164075993092 = 4067.82461732 inh2o
10 atm × (101,325/249.08891) = 4,067.824617 inh2o
Summary
To convert Atmosphere to inH2O, multiply the value in atm by (101325 Pa per atm) / (249.08891 Pa per inh2o). Equivalently: value_inh2o = value_atm × (101325 / 249.08891). Numerically, 1 atm equals 406.7824617322385 inh2o.
Relationship context
Both Atmosphere and inH2O are converted by fixed multiples of the pascal. Multiplying by (Pa per atm) ÷ (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
| Atmosphere (atm) | inH2O (inh2o) |
|---|---|
| 0.1 | 40.6782461732 |
| 1 | 406.782461732 |
| 2 | 813.564923464 |
| 3 | 1,220.3473852 |
| 4 | 1,627.12984693 |
| 5 | 2,033.91230866 |
| 6 | 2,440.69477039 |
| 7 | 2,847.47723213 |
| 8 | 3,254.25969386 |
| 9 | 3,661.04215559 |
| Atmosphere (atm) | inH2O (inh2o) |
|---|---|
| 10 | 4,067.82461732 |
| 20 | 8,135.64923464 |
| 30 | 12,203.473852 |
| 40 | 16,271.2984693 |
| 50 | 20,339.1230866 |
| 60 | 24,406.9477039 |
| 70 | 28,474.7723213 |
| 80 | 32,542.5969386 |
| 90 | 36,610.4215559 |
| 100 | 40,678.2461732 |