Convert Millimeters of Mercury to Millibars
Convert Millimeters of Mercury (mmHg) to Millibars (mbar) instantly and accurately.
Conversion Formula
mbar = mmHg × 1.333223874
About Millimeters of Mercury
One millimetre of mercury (mmHg) = pressure from 1 mm of mercury at 0°C and standard gravity = 133.322 Pa. Clinical medicine worldwide uses mmHg for blood pressure (normal ~120/80 mmHg) and for gas partial pressures in physiology: arterial O₂ ~95-100 mmHg; CO₂ ~40 mmHg; alveolar O₂ ~104 mmHg. Ophthalmologists measure intraocular pressure in mmHg (normal 10-21; glaucoma risk above 21). Vacuum equipment ratings are also given in mmHg. 760 mmHg = 1 atm. 1 mmHg = 133.322 Pa.
About Millibars
A millibar (mbar) = 100 Pa = 1 hPa - the historically dominant meteorological pressure unit. Standard sea-level pressure is 1013.25 mbar. Hurricane intensity is characterised by central pressure: Category 5 storms typically below 920 mbar (US record: 892 mbar, 1935). Upper-air analysis levels - 850, 700, 500, 300, 200 mbar - appear throughout decades of archived meteorological data. Aircraft cabins are pressurised to ~750-800 mbar at cruise altitude. 'Weather bombs' see pressure fall 24+ mbar in 24 hours. 1 mbar = 100 Pa.
Quick Reference Table
| Millimeters of Mercury (mmHg) | Millibars (mbar) |
|---|---|
| 1 mmHg | 1.33322 mbar |
| 2 mmHg | 2.66645 mbar |
| 5 mmHg | 6.66612 mbar |
| 10 mmHg | 13.3322 mbar |
| 25 mmHg | 33.3306 mbar |
| 50 mmHg | 66.6612 mbar |
| 100 mmHg | 133.322 mbar |