Pressure
atmtommHg
Convert standard atmospheres (atm) to millimetres of mercury (mmHg).
Factor1 atm = 759.9999 mmHg
Converter
atm
Accepts numbers or expressions, e.g. 150 + 14.7
Result
mmHg
Rendered to 6 significant figures.
Formula
Formula
mmHg = atm × 759.9999
Multiply any value in standard atmospheres by 759.9999 to obtain the value in millimetres of mercury.
Worked example
Convert 1 atm to mmHg.
- 01Start with 1 atm.
- 02Multiply by the conversion factor: 1 × 759.9999 = 760 mmHg.
Result1 atm = 760 mmHg
Conversion table
| atm | mmHg |
|---|---|
| 1 | 760 |
| 2 | 1520 |
| 5 | 3800 |
| 10 | 7600 |
| 20 | 15200 |
| 50 | 38000 |
| 100 | 76000 |
| 200 | 1.5200e+5 |
| 500 | 3.8000e+5 |
| 1000 | 7.6000e+5 |
Reference values rounded to 5 significant figures for display.
FAQ
What is the conversion factor from atm to mmHg?
1 atm equals 759.9999 mmHg. To convert, multiply the value in standard atmospheres by 759.9999.
How do I convert 1 atm to mmHg?
1 atm = 760 mmHg. For any value, multiply by 759.9999.
How do I convert mmHg back to atm?
Divide by the same factor — or equivalently, multiply by 0.00131579. So 1 mmHg = 0.00131579 atm.
When would I need to convert standard atmosphere to millimetre of mercury?
Pressure conversions between atm and mmHg 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).