Psi to Torr Converter
Enter the value that you want to convert psi to torr or torr to psi.
1 psi = 51.7149326 torr
Formula: torr = psi value × 51.7149326
psi to torr
10 psi = 517.14933 torr
Popular Pressure Converters:
Psi vs Torr
What is Psi?
Psi (psi) is a unit of pressure measurement. 1 psi is equal to 51.7149326 torr.
What is Torr?
Torr (Torr) is a unit of pressure measurement. 1 torr is equal to 0.0193368 psi.
Pressure Units Across Industries
Pressure measurements vary dramatically by industry. Meteorologists report in millibars or hectopascals, tire shops use PSI, scuba divers think in atmospheres or bar, vacuum engineers work in torr, and hydraulic systems specify in megapascals. A single industrial plant might encounter all these units across different equipment manuals, safety datasheets, and regulatory standards from different countries.
psi to torr metric conversion table
| 0.01 psi | = | 0.51715 Torr |
| 0.1 psi | = | 5.17149 Torr |
| 1 psi | = | 51.71493 Torr |
| 2 psi | = | 103.42987 Torr |
| 3 psi | = | 155.14480 Torr |
| 4 psi | = | 206.85973 Torr |
| 5 psi | = | 258.57466 Torr |
| 6 psi | = | 310.28960 Torr |
| 7 psi | = | 362.00453 Torr |
| 8 psi | = | 413.71946 Torr |
| 9 psi | = | 465.43439 Torr |
| 10 psi | = | 517.14933 Torr |
| 11 psi | = | 568.86426 Torr |
| 12 psi | = | 620.57919 Torr |
| 13 psi | = | 672.29412 Torr |
| 14 psi | = | 724.00906 Torr |
| 15 psi | = | 775.72399 Torr |
| 16 psi | = | 827.43892 Torr |
| 17 psi | = | 879.15385 Torr |
| 18 psi | = | 930.86879 Torr |
| 19 psi | = | 982.58372 Torr |
| 20 psi | = | 1034.29865 Torr |
| 30 psi | = | 1551.44798 Torr |
| 40 psi | = | 2068.59730 Torr |
| 50 psi | = | 2585.74663 Torr |
| 60 psi | = | 3102.89595 Torr |
| 70 psi | = | 3620.04528 Torr |
| 80 psi | = | 4137.19461 Torr |
| 90 psi | = | 4654.34393 Torr |
| 100 psi | = | 5171.49326 Torr |
| 200 psi | = | 10342.98651 Torr |
| 300 psi | = | 15514.47977 Torr |
| 400 psi | = | 20685.97303 Torr |
| 500 psi | = | 25857.46629 Torr |
| 600 psi | = | 31028.95954 Torr |
| 700 psi | = | 36200.45280 Torr |
| 800 psi | = | 41371.94606 Torr |
| 900 psi | = | 46543.43931 Torr |
| 1000 psi | = | 51714.93257 Torr |
How to Convert Psi to Torr?
We can convert psi to torr by using an example.
Example:
Convert 20 Psi to Torr?
We know 1 Psi = 51.7149326 torr; 1 Torr = 0.0193368 psi.
20 psi = ___Torr
20 × 51.7149326 = 1034.29865 Torr (we know 1 psi = 51.7149326 torr)
Answer:
20 psi = 1034.29865 torr
How to Convert PSI to Torr (Step-by-Step)
Converting PSI to torr is essential in vacuum engineering, freeze drying, and pharmaceutical lyophilization. The conversion factor is 1 PSI = 51.7149 torr.
- Write down the pressure value in PSI.
- Multiply the PSI value by 51.7149.
- The result is the equivalent pressure in torr.
- For quick estimation, multiply PSI by 52 (overshoots by ~0.6%).
Common PSI to Torr Conversions
Pressure values relevant to vacuum pumps, freeze drying, and low-pressure processes.
| Psi | Torr |
|---|---|
| 14.696 PSI | 760 torr |
| 10 PSI | 517.1 torr |
| 5 PSI | 258.6 torr |
| 1 PSI | 51.71 torr |
| 0.5 PSI | 25.86 torr |
| 0.1 PSI | 5.17 torr |
| 0.01 PSI | 0.517 torr |
| 0.001 PSI | 0.0517 torr |
Solved Examples: PSI to Torr
Question 1: A freeze dryer operates at 0.1 PSI absolute during primary drying. What is this in torr?
Solution:
Pressure in torr = 0.1 × 51.7149
= 5.17 torr
Answer: 0.1 PSI = 5.17 torr — within the optimal range (1-10 torr) for ice sublimation in lyophilization.
Question 2: A vacuum pump pulls down to 0.5 PSI absolute. Express the ultimate vacuum in torr.
Solution:
Pressure in torr = 0.5 × 51.7149
= 25.86 torr
Answer: 0.5 PSI = 25.86 torr — suitable for vacuum degassing and short-path distillation.
Question 3: A gauge reads -12 PSI (vacuum gauge pressure). What is the absolute pressure in torr?
Solution:
Absolute PSI = atmospheric - gauge vacuum = 14.7 - 12 = 2.7 PSI
Pressure in torr = 2.7 × 51.7149
= 139.6 torr
Answer: -12 PSI gauge = 2.7 PSI absolute = 139.6 torr — moderate vacuum level.
Question 4: A vacuum packaging machine operates at 1 PSI absolute. What is the chamber pressure in torr?
Solution:
Pressure in torr = 1 × 51.7149
= 51.71 torr
Answer: 1 PSI absolute = 51.71 torr — adequate for food vacuum packaging.
Practice Questions: PSI to Torr
Try solving these on your own to test your understanding:
- Convert 2 PSI to torr. (Answer: 103.4 torr)
- A rotary evaporator operates at 0.3 PSI absolute. Express in torr. (Answer: 15.51 torr)
- Convert 0.05 PSI to torr. (Answer: 2.59 torr)
- A vacuum gauge reads -14 PSI. What is the absolute pressure in torr? (Answer: 0.7 PSI abs = 36.2 torr)
- Convert 7 PSI absolute to torr. (Answer: 362.0 torr)
Freeze Drying (Lyophilization): PSI to Torr in Pharma
Pharmaceutical lyophilization cycles specify chamber pressure in torr (typically 0.05-1 torr for primary drying, 0.01-0.1 torr for secondary drying). US-made vacuum gauges often read in PSI or inches of mercury, requiring conversion. At 0.1 torr (0.002 PSI), ice sublimes at -40°C, preserving protein structure in biologics. Shelf temperature and chamber pressure (in torr) together control the sublimation rate — critical for product quality.
Vacuum Pump Selection: Matching PSI Ratings to Torr Requirements
Vacuum pump catalogs from US manufacturers (Welch, Edwards, Agilent) may specify ultimate pressure in PSI, Torr, mbar, or Pa. A typical rotary vane pump achieves 0.001 PSI (0.05 torr) ultimate vacuum. Scroll pumps reach 0.0001 PSI (0.005 torr). For processes requiring <0.001 torr, add a turbomolecular pump. Converting between PSI and torr specifications prevents mismatching pump capability to process requirements.
Vacuum Distillation in Chemical Processing
Short-path distillation and vacuum distillation reduce boiling points by lowering pressure. At 1 torr (0.019 PSI), many compounds boil 100-150°C below their atmospheric boiling point, preventing thermal decomposition. Cannabis distillation operates at 0.01-1 torr. Essential oil extraction uses 5-50 torr. Petroleum vacuum distillation (crude oil fractionation) operates at 25-100 torr (0.5-2 PSI absolute) to separate heavy fractions without cracking.
Key Takeaways
- 1 PSI = 51.7149 torr — multiply PSI by ~52 for quick conversion.
- Standard atmosphere: 14.696 PSI = 760 torr.
- Freeze drying primary drying: 1-10 torr (0.02-0.2 PSI).
- Vacuum distillation: 0.01-50 torr depending on application.
- Gauge vacuum must be converted to absolute before multiplying by 51.7.
- US vacuum gauges may read PSI absolute or inches of mercury — always verify.
Psi to Torr Conversion Formula
torr = psi × 51.7149326
1 psi = 51.7149326 torr
1 torr = 0.0193368 psi
Reverse: psi = torr × 0.0193368
Frequently Asked Questions
How many torr are in 1 psi?
There are 51.7149326 torr in 1 psi. To convert psi to torr, multiply the value by 51.7149326.
How do I convert psi to torr?
Multiply your psi value by 51.7149326 to get the equivalent in torr. For example, 5 psi = 5 × 51.7149326 = 258.57466 torr.
How do I convert torr to psi?
Multiply your torr value by 0.0193368 to get the equivalent in psi. Alternatively, divide by 51.7149326.
What is 10 psi in torr?
10 psi is equal to 517.14933 torr.
What is 100 psi in torr?
100 psi is equal to 5171.49326 torr.