Pressure
atmtocmH₂O
Convert standard atmospheres (atm) to centimetres of water column (cmH₂O).
Factor1 atm = 1033.227 cmH₂O
Converter
atm
Accepts numbers or expressions, e.g. 150 + 14.7
Result
cmH₂O
Rendered to 6 significant figures.
Formula
Formula
cmH₂O = atm × 1033.227
Multiply any value in standard atmospheres by 1033.227 to obtain the value in centimetres of water column.
Worked example
Convert 1 atm to cmH₂O.
- 01Start with 1 atm.
- 02Multiply by the conversion factor: 1 × 1033.227 = 1033.23 cmH₂O.
Result1 atm = 1033.23 cmH₂O
Conversion table
| atm | cmH₂O |
|---|---|
| 1 | 1033.2 |
| 2 | 2066.5 |
| 5 | 5166.1 |
| 10 | 10332 |
| 20 | 20665 |
| 50 | 51661 |
| 100 | 1.0332e+5 |
| 200 | 2.0665e+5 |
| 500 | 5.1661e+5 |
| 1000 | 1.0332e+6 |
Reference values rounded to 5 significant figures for display.
FAQ
What is the conversion factor from atm to cmH₂O?
1 atm equals 1033.227 cmH₂O. To convert, multiply the value in standard atmospheres by 1033.227.
How do I convert 1 atm to cmH₂O?
1 atm = 1033.23 cmH₂O. For any value, multiply by 1033.227.
How do I convert cmH₂O back to atm?
Divide by the same factor — or equivalently, multiply by 0.0009678411. So 1 cmH₂O = 0.000967841 atm.
When would I need to convert standard atmosphere to centimetre of water column?
Pressure conversions between atm and cmH₂O are common when working with mixed-vendor instrumentation, when piping codes use different units to process datasheets, or when converting field readings into SI for hydraulic calculations.
Is the conversion exact?
The factor shown is precise to at least 7 significant figures. For most process-engineering work this is far better than instrument accuracy. For metrology or trade applications, refer to the relevant national standard (NIST, BIPM, ISO 80000).