What is normal blood pressure in mmHg?

120/80 mmHg is considered normal adult blood pressure 120 mmHg (systolic) : Pressure in arteries when heart beats/contracts Upper number in blood pressure reading 80 mmHg (diastolic) : Pressure in arteries when heart rests between beats Lower number in blood pressure reading Blood pressure categories (American Heart Association) : Normal : <120/<80 mmHg Elevated : 120-129/<80 mmHg Stage 1 Hypertension : 130-139/80-89 mmHg Stage 2 Hypertension : ≥140/90 mmHg Hypertensive Crisis : >180/120 mmHg (seek emergency care)

How do I convert mmHg to PSI?

Formula : PSI = mmHg × 0.0193368 Examples : 120 mmHg = 2.32 PSI (systolic blood pressure) 80 mmHg = 1.55 PSI (diastolic blood pressure) 760 mmHg = 14.7 PSI (atmospheric pressure) 100 mmHg = 1.93 PSI 10 mmHg = 0.19 PSI mmHg to PSI converter →

Why is blood pressure measured in mmHg?

Historical : Early sphygmomanometers (blood pressure cuffs) used mercury columns Standardization : Established globally since early 1900s Accuracy : Mercury barometers very accurate and reliable Consistency : Changing units would cause confusion in medical field Universal : Understood by doctors, nurses, patients worldwide Modern devices : Digital monitors still display mmHg for consistency, even though they don't use actual mercury. Why not change? : Medical literature, guidelines all use mmHg Training and education based on mmHg Patient familiarity (everyone knows "120 over 80") Risk of errors during transition period

What is the difference between mmHg and Torr?

Virtually identical : 1 mmHg ≈ 1 Torr (difference < 0.000015%) mmHg (Millimeter of Mercury) : Based on mercury density at 0°C, standard gravity Slightly temperature/gravity dependent Preferred in medicine (blood pressure) Torr : Defined as exactly 1/760 atmosphere Independent of mercury properties Preferred in vacuum technology, physics Practical usage : Treat them as equal—difference is negligible for all practical purposes. Conversion : 1 mmHg = 1.000000142 Torr (effectively 1:1) mmHg to Torr converter →

How many mmHg is 1 atmosphere?

1 atm = 760 mmHg (exactly, by definition) This is the height of mercury column supported by atmospheric pressure at sea level. Examples : 0.5 atm = 380 mmHg 1 atm = 760 mmHg (sea level) 2 atm = 1,520 mmHg (diving 10m deep) 3 atm = 2,280 mmHg (diving 20m deep) Altitude effect : Sea level: 760 mmHg Denver (1,609m): ~630 mmHg La Paz, Bolivia (3,640m): ~480 mmHg Mount Everest (8,848m): ~253 mmHg Atmosphere to mmHg converter →

Will medicine switch from mmHg to kPa?

Slow transition, likely decades away (if ever) Current status : Still dominant : Most medical equipment worldwide uses mmHg Some countries transitioning : Australia, Canada partially adopted kPa Dual display : Modern monitors often show both mmHg and kPa Guidelines : International medical guidelines still primarily use mmHg Challenges to switching : Familiarity : "120/80" universally understood Education : Medical training globally uses mmHg Communication : Doctor-patient communication simpler with mmHg Standards : Hypertension thresholds defined in mmHg Risk : Potential for medication errors during transition Conversion : 120/80 mmHg = 16.0/10.7 kPa (less intuitive) Prediction : mmHg likely to persist in medicine for foreseeable future despite SI adoption elsewhere.

Millimeter of Mercury (mmHg) - Unit Information & Conversion

Symbol:mmHg

Plural:millimeters of mercury

Category:Pressure

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What is a Millimeter of Mercury?

Millimeter of mercury (mmHg) measures pressure by mercury column height. Universal standard for blood pressure (120/80 mmHg normal). 1 mmHg ≈ 133.322 Pa ≈ 1 Torr. 760 mmHg = 1 atmosphere. Still used in medicine despite SI adoption.

History of the Millimeter of Mercury

Based on Torricelli mercury barometer (1643). Evangelista Torricelli demonstrated atmospheric pressure supports 760mm mercury column at sea level. Became standard for blood pressure, barometric measurement. Persists in medicine for historical consistency.

Quick Answer

What is mmHg? Millimeter of mercury (mmHg) measures pressure by height of mercury column it supports. Universal standard for blood pressure measurement (120/80 mmHg = normal). 1 mmHg ≈ 133.322 Pa ≈ 1 Torr. 760 mmHg = sea level atmospheric pressure. Use our pressure converter for conversions.

Definition

1 mmHg = 133.322 Pa = 0.133 kPa ≈ 1 Torr (0.000015% difference) = 1/760 atm = 0.0193 PSI

Standard relationships:

760 mmHg = 1 atmosphere (standard pressure)
1 mmHg ≈ 1 Torr (virtually identical)
1 mmHg = 1.333 mbar

Common Uses

Medicine: Blood pressure (universal standard), intracranial pressure, intraocular pressure. Meteorology: Barometric pressure (historical, now mostly hPa/mbar). Laboratory: Gas pressures, vacuum measurements, vapor pressure. Aviation: Altimeter settings (older aircraft, some regions).

Real-World Examples

Blood Pressure (Primary Use)

Normal adult: 120/80 mmHg
- Systolic (120): Pressure when heart contracts
- Diastolic (80): Pressure when heart relaxes
Elevated: 120-129/<80 mmHg
Hypertension Stage 1: 130-139/80-89 mmHg
Hypertension Stage 2: ≥140/90 mmHg
Hypertensive crisis: >180/120 mmHg (emergency)
Hypotension: <90/60 mmHg
Severe hypotension: <70/40 mmHg

Specialized Medical Pressures

Intracranial pressure (normal): 5-15 mmHg
Intracranial pressure (elevated): >20 mmHg
Intraocular pressure (normal): 10-21 mmHg
Intraocular pressure (glaucoma): >21 mmHg
Central venous pressure: 2-8 mmHg
Pulmonary artery pressure: 15-30/4-12 mmHg

Atmospheric Pressure (Historical)

Sea level (standard): 760 mmHg (exactly 1 atm)
High pressure system: 770-800 mmHg (fair weather)
Normal range: 745-775 mmHg
Low pressure system: 730-750 mmHg (storms)
Hurricane: 670-700 mmHg (severe)
Denver (1,609m): ~630 mmHg
Mount Everest summit: ~253 mmHg

Vacuum & Laboratory

Rough vacuum: 1-760 mmHg
Medium vacuum: 0.001-1 mmHg
High vacuum: <0.001 mmHg
Blood pressure cuff: 0-300 mmHg range
Manometer (laboratory): Directly measures mmHg

Vapor Pressures (Chemistry)

Water (room temperature, 25°C): 23.8 mmHg
Water (body temperature, 37°C): 47 mmHg
Water (boiling, 100°C): 760 mmHg
Ethanol (25°C): 59 mmHg
Diethyl ether (25°C): 442 mmHg

Millimeter of Mercury Conversion Formulas

To Pascal:

1 mmHg = 133.322368 Pa

Example: 5 millimeters of mercury = 666.611842 pascals

To Kilopascal:

1 mmHg = 0.133322 kPa

Example: 5 millimeters of mercury = 0.666612 kilopascals

To Megapascal:

1 mmHg = 0.000133 MPa

Example: 5 millimeters of mercury = 0.000667 megapascals

To Hectopascal:

1 mmHg = 1.333224 hPa

Example: 5 millimeters of mercury = 6.666118 hectopascals

To Bar:

1 mmHg = 0.001333 bar

Example: 5 millimeters of mercury = 0.006666 bars

To Millibar:

1 mmHg = 1.333224 mbar

Example: 5 millimeters of mercury = 6.666118 millibars

To Atmosphere:

1 mmHg = 0.001316 atm

Example: 5 millimeters of mercury = 0.006579 atmospheres

To Technical Atmosphere:

1 mmHg = 0.00136 at

Example: 5 millimeters of mercury = 0.006798 technical atmospheres

To Torr:

1 mmHg = 1 Torr

Example: 5 millimeters of mercury = 5 torr

To Inch of Mercury:

1 mmHg = 0.03937 inHg

Example: 5 millimeters of mercury = 0.19685 inches of mercury

To Pound per Square Inch:

1 mmHg = 0.019337 psi

Example: 5 millimeters of mercury = 0.096684 pounds per square inch

To Kilopound per Square Inch:

1 mmHg = 0.000019 ksi

Example: 5 millimeters of mercury = 0.000097 kilopounds per square inch

To Kilogram-force per Square Centimeter:

1 mmHg = 0.00136 kgf/cm²

Example: 5 millimeters of mercury = 0.006798 kilograms-force per square centimeter

To Kilogram-force per Square Meter:

1 mmHg = 13.595098 kgf/m²

Example: 5 millimeters of mercury = 67.97549 kilograms-force per square meter

To Millimeter of Water Column:

1 mmHg = 13.595098 mmH₂O

Example: 5 millimeters of mercury = 67.97549 millimeters of water column

To Inch of Water Column:

1 mmHg = 0.53524 inH₂O

Example: 5 millimeters of mercury = 2.6762 inches of water column

Frequently Asked Questions

120/80 mmHg is considered normal adult blood pressure 120 mmHg (systolic):

Pressure in arteries when heart beats/contracts
Upper number in blood pressure reading 80 mmHg (diastolic):
Pressure in arteries when heart rests between beats
Lower number in blood pressure reading Blood pressure categories (American Heart Association):
Normal: <120/<80 mmHg
Elevated: 120-129/<80 mmHg
Stage 1 Hypertension: 130-139/80-89 mmHg
Stage 2 Hypertension: ≥140/90 mmHg
Hypertensive Crisis: >180/120 mmHg (seek emergency care)

Convert Millimeter of Mercury

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Millimeter of Mercury Quick Info

mmHg

Symbol:mmHg

Category:Pressure

System:Various

Convert Millimeter of Mercury

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Millimeter of Mercury (mmHg) - Unit Information & Conversion

🔄 Quick Convert Millimeter of Mercury

What is a Millimeter of Mercury?

History of the Millimeter of Mercury

Quick Answer

Definition

Common Uses

Real-World Examples

Blood Pressure (Primary Use)

Specialized Medical Pressures

Atmospheric Pressure (Historical)

Vacuum & Laboratory

Vapor Pressures (Chemistry)

Millimeter of Mercury Conversion Formulas

Frequently Asked Questions

What is normal blood pressure in mmHg?

How do I convert mmHg to PSI?

Why is blood pressure measured in mmHg?

What is the difference between mmHg and Torr?

How many mmHg is 1 atmosphere?

Will medicine switch from mmHg to kPa?

Convert Millimeter of Mercury

Millimeter of Mercury Quick Info

Related Pressure Units

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