Pressure
atmtohPa
Convert standard atmospheres (atm) to hectopascals (hPa).
Factor1 atm = 1013.25 hPa
Converter
atm
Accepts numbers or expressions, e.g. 150 + 14.7
Result
hPa
Rendered to 6 significant figures.
Formula
Formula
hPa = atm × 1013.25
Multiply any value in standard atmospheres by 1013.25 to obtain the value in hectopascals.
Worked example
Convert 1 atm to hPa.
- 01Start with 1 atm.
- 02Multiply by the conversion factor: 1 × 1013.25 = 1013.25 hPa.
Result1 atm = 1013.25 hPa
Conversion table
| atm | hPa |
|---|---|
| 1 | 1013.3 |
| 2 | 2026.5 |
| 5 | 5066.3 |
| 10 | 10133 |
| 20 | 20265 |
| 50 | 50663 |
| 100 | 1.0133e+5 |
| 200 | 2.0265e+5 |
| 500 | 5.0663e+5 |
| 1000 | 1.0133e+6 |
Reference values rounded to 5 significant figures for display.
FAQ
What is the conversion factor from atm to hPa?
1 atm equals 1013.25 hPa. To convert, multiply the value in standard atmospheres by 1013.25.
How do I convert 1 atm to hPa?
1 atm = 1013.25 hPa. For any value, multiply by 1013.25.
How do I convert hPa back to atm?
Divide by the same factor — or equivalently, multiply by 0.0009869233. So 1 hPa = 0.000986923 atm.
When would I need to convert standard atmosphere to hectopascal?
Pressure conversions between atm and hPa 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).