Convert PSI to Torr
Convert PSI to Torr instantly. 1 PSI (psi) equals 51.7149 Torr (Torr).
PSI to Torr conversion table
| PSI (psi) | Torr (Torr) |
|---|---|
| 1 psi | 51.7149 Torr |
| 2 psi | 103.4299 Torr |
| 3 psi | 155.1448 Torr |
| 5 psi | 258.5747 Torr |
| 10 psi | 517.1493 Torr |
| 20 psi | 1,034.3 Torr |
| 50 psi | 2,585.75 Torr |
| 100 psi | 5,171.49 Torr |
| 500 psi | 25,857.47 Torr |
| 1,000 psi | 51,714.93 Torr |
1 PSI = 51.7149 Torr · multiply PSI by 51.7149
About converting PSI to Torr
PSI (psi) and Torr (Torr) are both units of pressure, so converting between them is a single multiplication: multiply your PSI figure by 51.7149. Ten PSI comes to 517.1493 Torr, and a hundred works out at 5,171.49 Torr.
Rule of thumb: going from PSI to Torr multiplies, so the figure always grows — one PSI is already 51.7149 Torr. If your answer came out smaller, you have the conversion the wrong way round.
What is a PSI?
Pounds per square inch is the pressure unit Americans actually meet: on the gauge at the filling-station air pump, on compressors, on hydraulic equipment, and on the sidewall of every tyre sold in the country. It survives in British tyre pressures too, despite nearly everything else there having gone metric. Structurally it is exactly what the name says — a pound-force resting on a square inch — and that heritage is also its weakness, because it inherits the pound-force and with it the old confusion between pounds as weight and pounds as mass.
What is a Torr?
The torr is named after Evangelista Torricelli, who invented the mercury barometer and in the process produced the first sustained vacuum anyone had made. The unit fits that legacy exactly: it is very nearly the pressure of one millimetre of mercury, and it is still the working unit of vacuum technology, where gauges read in torr and in decimal fractions of it. Its most familiar relative is not in a laboratory at all — blood pressure is quoted in millimetres of mercury, essentially the same size, so a reading of 120 over 80 is a pressure measurement in all but name.
To put both in perspective: a car tyre is usually inflated to about 32 psi, while a rough vacuum pump pulls down to about 0.1 torr.
The converter above updates as you type, and the table lists common values for quick reference. Need the opposite direction? Use the Torr to PSI converter, or browse all Pressure converters.
Frequently asked questions
How many Torr are in one PSI?
There are 51.7149 Torr in one PSI.
How do I convert PSI to Torr?
Multiply the number of PSI by 51.7149. For example, 10 PSI = 517.1493 Torr.
What is 100 PSI in Torr?
100 PSI is equal to 5,171.49 Torr.
How do I convert Torr to PSI?
Multiply the Torr value by 0.01934 (or divide by 51.7149).
Is this PSI to Torr conversion exact?
The definition is exact — PSI and Torr are both fixed against the same base by international agreement — but the decimal shown here is rounded for readability, because the true ratio does not terminate. For engineering or scientific work, carry more decimal places than this page displays.
What is a PSI?
Pounds per square inch is the pressure unit Americans actually meet: on the gauge at the filling-station air pump, on compressors, on hydraulic equipment, and on the sidewall of every tyre sold in the country. It survives in British tyre pressures too, despite nearly everything else there having gone metric. Structurally it is exactly what the name says — a pound-force resting on a square inch — and that heritage is also its weakness, because it inherits the pound-force and with it the old confusion between pounds as weight and pounds as mass.
What is a Torr?
The torr is named after Evangelista Torricelli, who invented the mercury barometer and in the process produced the first sustained vacuum anyone had made. The unit fits that legacy exactly: it is very nearly the pressure of one millimetre of mercury, and it is still the working unit of vacuum technology, where gauges read in torr and in decimal fractions of it. Its most familiar relative is not in a laboratory at all — blood pressure is quoted in millimetres of mercury, essentially the same size, so a reading of 120 over 80 is a pressure measurement in all but name.