Millimeter of mercury

The millimeter of mercury (mmHg or mm Hg) is a widely recognized unit of pressure, often used in medical and scientific contexts. It's particularly valuable in measuring blood pressure and describing low-pressure conditions in fluid systems.

Definition and Usage

The millimeter of mercury is defined as the pressure exerted by a column of mercury one millimeter in height at the standard acceleration due to gravity. This unit is commonly utilized in both medical and scientific applications to measure and communicate pressure values.

Applications in Medicine and Science

The millimeter of mercury serves important purposes:

  • Medical Blood Pressure: It's used in measuring systolic and diastolic blood pressure.
  • Vacuum Systems: Engineers apply it to describe low pressure in vacuum systems.
  • Fluid Dynamics: Scientists use it to measure pressure variations in fluid flows.

Conversions and Equivalents

Understanding conversions of millimeter of mercury to other pressure units is essential:

  • 1 Millimeter of Mercury (mmHg) = 133.322 Pascal (Pa)
  • 1 Millimeter of Mercury (mmHg) ≈ 1.33322 mbar
  • 1 Millimeter of Mercury (mmHg) ≈ 0.00133322 bar
  • 1 Millimeter of Mercury (mmHg) ≈ 0.0193368 psi

Usage in Medical and Scientific Fields

The millimeter of mercury plays a crucial role in various contexts:

  • Medical Diagnosis: It's essential in measuring blood pressure and diagnosing hypertension.
  • Barometric Pressure: Millimeter of mercury helps describe atmospheric pressure.
  • Fluid Analysis: Scientists use it to study fluid dynamics and pressure changes.


The millimeter of mercury (mmHg) is a fundamental unit of pressure, especially in medical and scientific applications. Its significance in measuring blood pressure and describing pressure values in fluid systems makes it an indispensable tool for medical professionals, researchers, and engineers.

Keywords: Millimeter of Mercury, mmHg, pressure unit, medical applications, fluid dynamics, conversions