atm to inH2O converter
1 atm = 406.794 inH2O
And 1 inH2O = 0.00245825 atm. Standard atmosphere to inches of water column.
Formula
inH2O = atm × 406.794
A reading of 15 atm is 15 × 406.794 = 6,101.91 inH2O.
atm to inH2O table
| atm | inH2O |
|---|---|
| 1 atm | 406.794 inH2O |
| 5 atm | 2,033.97 inH2O |
| 10 atm | 4,067.94 inH2O |
| 15 atm | 6,101.91 inH2O |
| 30 atm | 12,203.8 inH2O |
| 50 atm | 20,339.7 inH2O |
| 100 atm | 40,679.4 inH2O |
| 500 atm | 203,397 inH2O |
| 1,000 atm | 406,794 inH2O |
inH2O to atm table
| inH2O | atm |
|---|---|
| 1 inH2O | 0.00245825 atm |
| 5 inH2O | 0.0122912 atm |
| 10 inH2O | 0.0245825 atm |
| 15 inH2O | 0.0368737 atm |
| 30 inH2O | 0.0737474 atm |
| 50 inH2O | 0.122912 atm |
About these units
atm (standard atmosphere): Defined as 101,325 Pa, roughly sea-level air pressure.
inH2O (inches of water column): Low duct and furnace pressures, at the conventional 4 °C water reference.
Gauge pressure (psig, barg) is measured relative to the surrounding atmosphere; absolute pressure (psia, bara) is relative to vacuum. Converting units never changes that reference: absolute = gauge + about 14.696 psi (1.01325 bar) at sea level. Stress uses the same units: 1 MPa = 1 N/mm².
Convert inH2O to atm instead · All pressure and stress conversions