Psi to Torr
An instant psi-to-torr converter, with the formula and a reference table below.
| Psi | Torr |
|---|---|
| 1 psi | 51.714933 Torr |
| 2 psi | 103.429865 Torr |
| 3 psi | 155.144798 Torr |
| 5 psi | 258.574663 Torr |
| 10 psi | 517.149326 Torr |
| 25 psi | 1292.873314 Torr |
| 50 psi | 2585.746629 Torr |
| 100 psi | 5171.493257 Torr |
How to use
- Enter a value in the Psi field.
- The Torr figure appears immediately — no button to press.
- Typing in the Torr field converts back to Psi the same way.
- Use the reference table for the values that come up most often.
Psi to Torr formula
Converting psi to torr is a single multiplication by 51.7149326.
Torr = psi × 51.7149326
Why this factor: the pound per square inch and the torr are both defined against the pascal, so dividing one definition by the other gives 51.7149326 directly. Both definitions are set out in full below.
To go the other way, divide by 51.7149326 — or use the Torr to Psi converter, which is the same calculation reversed.
Worked example
Given 32 psi, multiplying by 51.7149326 yields 1654.877842 Torr.
32 psi × 51.7149326 = 1654.877842 Torr
The converter above does this for any value you type, in either direction.
What is a pound per square inch?
Pounds per square inch is the standard pressure unit in the United States.
Definition: One pound-force per square inch, which is about 6,894.757 pascals.
Where it is used: US tire pressure, compressed air and hydraulic systems, and plumbing water pressure.
What is a torr?
A torr is a vacuum-measurement pressure unit, defined as one 760th of a standard atmosphere.
Definition: Exactly 101,325/760 pascals, which is about 133.3224 Pa. Named after Evangelista Torricelli.
Where it is used: Vacuum systems, mass spectrometry, and semiconductor process chambers.
Worth knowing: Almost identical to the mmHg but not exactly equal — they differ by about one part in seven million, which matters only in precision metrology.
Psi vs Torr
The pound per square inch is a US customary unit while the torr is a specialized unit. That is why the factor between them is not a round number: the two systems were defined independently and only later tied together by exact agreement.
Frequently asked questions
How many torr are in a pound per square inch?
One pound per square inch equals 51.7149326 torr.
What is the formula to convert psi to torr?
Multiply the number of psi by 51.7149326. To reverse it, divide by 51.7149326 instead.
How do I convert torr back to psi?
Divide by 51.7149326, which is the same as multiplying by 0.0193367747.
How many torr are in 10 psi?
10 psi works out to 517.149326 Torr.
Is there anything to watch out for with torr?
Almost identical to the mmHg but not exactly equal — they differ by about one part in seven million, which matters only in precision metrology.
How is the pound per square inch defined?
One pound-force per square inch, which is about 6,894.757 pascals.