Convert Psi to Torr (Torr)
1 psi equals 51.7149 torr.
Psi to Torr Converter
How to Convert Psi to Torr
1 psi = 51.7149 torr
Torr = Psi × 51.7149
Example: 1 psi × 51.7149 = 51.7149 Torr
Reverse Conversion
To convert torr back to psi:
- Remember, 1 torr equals 0.0193368 psi.
- To convert 51.7149 Torr to psi, multiply
51.7149 x 0.0193368, resulting in1 psi.
Psi to torr Conversion Table
Reference table with common psi to torr conversions. All values calculated with high precision.
Psi to Torr Table
0.0001 to 12
Psi to Torr Table
1 to 100000
Torr to Psi Table
0.01 to 50
Torr to Psi Table
100 to 10000000
Definition of Psi
PSI: Pound per Square Inch
PSI (pound-force per square inch or lbf/in²) is a unit of pressure commonly used in the United States and other countries that use imperial units. It measures the force in pounds applied to an area of one square inch. PSI is widely used for tire pressure, hydraulic systems, pneumatic tools, and various industrial applications.
Conversions to Other Units of Measurement:
- Bar: 1 psi equals approximately 0.0689476 bar. This conversion is essential for international equipment specifications. For example, 30 psi equals approximately 2.07 bar.
- Pascal (Pa): 1 psi equals approximately 6,894.76 pascals. This conversion connects imperial to SI units. For example, 14.7 psi (approximately 1 atm) equals about 101,325 Pa.
- Kilopascal (kPa): 1 psi equals approximately 6.89476 kPa. This is frequently used in automotive and engineering contexts. For example, a tire pressure of 32 psi equals approximately 220.6 kPa.
- Atmosphere (atm): 1 psi equals approximately 0.068046 atm. Standard atmospheric pressure (1 atm) equals approximately 14.696 psi.
- Kilogram-force per square centimeter (kgf/cm²): 1 psi equals approximately 0.070307 kgf/cm². This conversion is used in older metric equipment.
PSI remains the dominant pressure unit in North America for everyday applications like tire inflation, air compressors, and blood pressure (though medical uses mmHg).
- Definition
- Imperial/US customary pressure unit equal to one pound-force per square inch.
- Exact factor
- 1 psi = 6,894.757293168... Pa
- Common equivalents
- 1 psi ≈ 0.0689476 bar
- 1 psi ≈ 6.89476 kPa
- 14.696 psi ≈ 1 atm
- Sources
Definition of Torr
Torr: The Vacuum Technologist's Unit
The torr is a unit of pressure named after the Italian physicist Evangelista Torricelli, inventor of the barometer. One torr is defined as exactly 1/760 of a standard atmosphere (101,325/760 Pa ≈ 133.322 Pa). The torr is widely used in vacuum technology, physics laboratories, and high-vacuum applications where precise low-pressure measurements are needed.
Conversions to Other Units of Measurement:
- Atmosphere (atm): 1 torr equals exactly 1/760 atm. By definition, 760 torr equals exactly 1 standard atmosphere.
- Pascal (Pa): 1 torr equals approximately 133.322 pascals. This converts vacuum readings to SI units.
- Millibar (mbar): 1 torr equals approximately 1.33322 mbar. This conversion is useful for relating vacuum levels to atmospheric measurements.
- Millimeter of Mercury (mmHg): 1 torr is very close to 1 mmHg (they differ by about 0.000015%). For practical purposes, they are often used interchangeably.
- Micron (μm Hg or mTorr): 1 torr equals 1,000 millitorr (mTorr) or microns. This is commonly used for high-vacuum measurements.
The torr provides a convenient scale for vacuum measurements, where typical applications range from rough vacuum (760-1 torr) to high vacuum (10⁻³-10⁻⁹ torr).
- Definition
- Pressure unit equal to exactly 1/760 of a standard atmosphere.
- Exact factor
- 1 Torr = 101,325/760 Pa = 133.32236842... Pa
- Common equivalents
- 760 Torr = 1 atm (exact by definition)
- 1 Torr ≈ 1 mmHg
- 1 Torr ≈ 1.33322 mbar
- Sources
About the Psi
Facts & Uses
- Pounds per square inch — the dominant pressure unit in US and UK engineering. 1 psi = 6894.757 Pa (derived from 1 lbf and 1 in², not exact in SI).
- Standard for US tire pressure (cars 30-35 psi, bicycles 60-100 psi), plumbing (40-80 psi household water), and compressed air tools.
- Common in gauge measurements: psig (gauge, relative to atmospheric) vs psia (absolute, including atmospheric pressure of 14.7 psi).
- Used in scuba diving in the US (3000 psi tanks), oil & gas industry, boiler ratings, and welding cylinders.
Curiosities
- 1 atm = 14.696 psi exactly — the value taught in US chemistry classes as the standard reference for sea-level pressure.
- The pressure inside a champagne bottle is 5-6 bar (75-90 psi) — about three times typical car tire pressure, which is why corks fly with such force.
- The deepest point in the Mariana Trench exerts about 16,000 psi (110 MPa) — over 1000 atmospheres.
- Approximate equivalents: 14.7 psi ≈ 1 atm ≈ 1.01 bar ≈ 101.3 kPa ≈ 760 mmHg.
Sources
About the Torr
Facts & Uses
- 1 torr = 1/760 of a standard atmosphere exactly = 101325/760 Pa ≈ 133.322 Pa. Numerically equal to 1 mmHg under standard conditions.
- Named after Evangelista Torricelli (1608-1647), the inventor of the mercury barometer in 1643.
- Standard in vacuum technology: ultra-high vacuum systems measured in milli-torr or micro-torr; semiconductor manufacturing uses torr for chamber pressures.
- Still common in medical contexts for blood pressure (interchangeable with mmHg) and partial pressures of gases in respiratory physiology.
Curiosities
- The torr is essentially equivalent to mmHg at standard conditions, but the torr is defined exactly while mmHg depends on mercury density and gravity.
- Torricelli's 1643 experiment was the first scientific demonstration of atmospheric pressure — a glass tube filled with mercury inverted into a basin showed the column standing at ~760 mm.
- A perfect vacuum would be 0 torr; the lowest practical vacuum in commercial systems is about 10⁻¹¹ torr — used in surface science and accelerators.
- Approximate equivalents: 760 torr = 1 atm; 1 torr ≈ 133 Pa ≈ 0.0193 psi.
Sources
Frequently Asked Questions
How many torr are in one psi?
One psi equals 51.7149 torr. To convert, multiply the psi value by 51.7149. For the reverse, divide the torr value by 51.7149 (or multiply by 0.0193368).
What is 10 psi in torr?
10 psi = 517.15 torr. This is one of the most commonly searched conversions for this pair.
How precise is the psi-to-torr conversion?
The factor 51.7149 is accurate to 6 significant figures, derived from international measurement standards. Our calculator uses full precision internally.
Looking for the reverse? Convert Torr to Psi
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