standard atmosphere to inch of water at 4°C
Convert standard atmosphere (atm) to inch of water at 4°C (inH₂O). Use an editable pressure converter, conversion formula, and reference table.
1 atm = 406.7824617 inH₂O
Conversion formula
One standard atmosphere equals 406.7824617 inch of water at 4°C. Multiply your value in standard atmosphere by this factor to get inch of water at 4°C. For the reverse conversion, divide by the same factor.
Worked example
To convert 5 standard atmosphere:5 × 406.7824617 = 2,033.912309 inH₂O
Conversion table
| standard atmosphere (atm) | inch of water at 4°C (inH₂O) |
|---|---|
| 0.01 | 4.067824617 |
| 0.1 | 40.67824617 |
| 1 | 406.7824617 |
| 2 | 813.5649235 |
| 5 | 2,033.912309 |
| 10 | 4,067.824617 |
| 25 | 10,169.56154 |
| 50 | 20,339.12309 |
| 100 | 40,678.24617 |
| 1000 | 406,782.4617 |
About these measurements
Pressure is force per unit of area.
The base reference used here is the pascal. One standard atmosphere is 101,325 base units; one inch of water at 4°C is 249.08891 base units.
Important distinctions
Gauge and absolute pressures must not be mixed. This converts units without changing the reference pressure.
Precision
The converter uses stored conversion factors and floating-point arithmetic. Results display up to ten significant digits, switching to scientific notation for very small or large values. Keep the precision of your original measurement when reporting results.
Common questions
How do I convert atm to inH₂O?
Multiply the quantity in atm by 406.7824617. You can also type the value into the converter above.
Can I reverse the conversion?
Yes. Use the swap button or open the inch of water at 4°C to standard atmosphere converter.
Reference
NIST Guide to the SI — conversion factors and prefix conventions. SI prefixes scale units by powers of ten; the dimension-specific notes above describe the assumptions used on this page.
