Pounds per square inch.
PSI to Torrs Converter — psi to Torr
Convert PSI (psi) to Torr (Torr) using the exact conversion factor (1 psi = 51.71493257 torr). See the formula, worked examples, conversion table, history, and common uses.
PSI to Torrs converter
Converter
Engineering Converter
Convert common stress, force, torque, power, and energy units used in engineering.
Context values
Some unit families need one extra value for a physically accurate result.
A torr is 1/760 standard atmosphere.
Result = input x 6894.757293 / 133.3223684.
Stress Pressure units are compatible.
Reserved above the conversion cards and below the converter.
About Converting PSI to Torrs
PSI and Torr both measure a quantity used in structural or mechanical engineering — commonly stress, pressure, force, torque, power, or energy — where converting between the unit conventions used in different regions, industries, or equipment specifications is a routine part of design work. PSI is most often used for tire pressure specifications in the us.
Formula
torrs = psi × 51.7149325715
This factor comes from each unit's defined relationship to the category's base unit: 1 psi equals 6894.75729317 base units, and 1 torr equals 133.322368421 base units, so dividing one by the other gives the direct psi-to-torr factor of 51.7149325715.
Simple example
1 psi × 51.71493257 = 51.71493257 Torr
1 psi = 51.71493257 torrs.
Real-world example
100 psi × 51.71493257 = 5,171.493257 Torr
100 psi = 5,171.493257 torrs.
Conversion table
| PSI (psi) | Torr (Torr) |
|---|---|
| 1 psi | 51.71493257 Torr |
| 10 psi | 517.1493257 Torr |
| 50 psi | 2,585.746629 Torr |
| 100 psi | 5,171.493257 Torr |
| 500 psi | 25,857.46629 Torr |
| 1,000 psi | 51,714.93257 Torr |
Reverse conversion: Torr to PSI
51.71493257 Torr × 0.0193367747 = 1 psi
51.71493257 torrs = 1 psi.
psi = torrs × 0.0193367747046
For a page dedicated to this direction, see Torr to PSI.
Understanding the PSI
PSI (psi) measures pressure. PSI (pounds-force per square inch) equals exactly 6,894.757293168 pascals. It is classified as a US/imperial customary unit.
Where it's used: United States (standard pressure unit for tires, tools, and plumbing)
Uses of the PSI today
- Tire pressure specifications in the US
- Hydraulic and pneumatic system ratings
- Plumbing, compressed-air tools, and industrial equipment ratings
History of the PSI
PSI is a derived unit from the pound-force and the inch, both themselves standardized through English and later international agreements rather than invented as a pressure unit from scratch.
It became the default pressure unit in US engineering as pound-force and inch-based measurement dominated American industry through the 19th and 20th centuries, and it remains in everyday use for tires and tools even as most other measurements in the US context stay imperial.
Historical origin. PSI was not the invention of a single named person; it developed through the process described above.
Understanding the Torr (Torr)
A torr is 1/760 standard atmosphere.
PSI — sources
- NIST Special Publication 811 — Guide for the Use of the International System of Units — Documents conversion factors for psi and other US customary pressure units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many torrs are in 1 psi?
1 psi equals 51.71493257 torrs, using the exact defined conversion factor rather than an estimate.
How do I convert psi to torr?
Multiply the psi value by 51.71493257. The converter above does this instantly to whatever precision you set.
How do I convert torr back to psi?
Use the reverse factor: 1 torr equals 0.0193367747 psi. You can also use the swap control in the converter above to flip the direction instantly.
What is a psi?
PSI (psi) measures pressure. PSI (pounds-force per square inch) equals exactly 6,894.757293168 pascals. It is classified as a US/imperial customary unit.
What is a torr?
Torr (Torr) is a unit of engineering.
Is the psi to torr conversion exact?
Yes. PSI (pounds-force per square inch) equals exactly 6,894.757293168 pascals. That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.
Where is the psi still used today?
United States (standard pressure unit for tires, tools, and plumbing)
Why do engineering unit conventions vary so much by region and industry?
Pressure, force, and stress can be expressed in metric (pascal, newton), US customary (psi, pound-force), or older and industry-specific units (atmosphere, torr, kip) depending on the country, industry, and even the equipment manufacturer, which is why engineers routinely need to convert between them when working across specs from different sources.