In 1 millitorr there are 0.0000193368 pounds per square inch. Meanwhile in 1 pounds per square inch there are 51,714.930373 millitorr. Keep reading to learn more about each unit of measure and how they are calculated. Or just use the Pounds per square inch to Millitorr calculator above to convert any number.
* Values rounded to 6 decimal places for readability
To convert millitorr (mTorr) to pounds per square inch (psi), convert millitorr to torr first, then apply the psi conversion.
Step 1: Convert millitorr to torr
1,000 mTorr = 1 Torr, so Torr = mTorr ÷ 1,000
Step 2: Convert torr to psi
Use this conversion factor: 1 Torr = 0.019336774741554 psi
Formula (mTorr to psi):
psi = (mTorr ÷ 1,000) × 0.019336774741554
Or, as a single factor: psi = mTorr × 0.000019336774741554
Quick example:
500 mTorr → 500 × 0.000019336774741554 = 0.009668387370777 psi
Millitorr (mTorr) is a unit of pressure. It equals one-thousandth of a torr. Torr is based on the pressure from a 1-millimeter column of mercury (mmHg), so mTorr is a very small pressure unit.
Pounds per square inch (psi) measures pressure as force over area. It means how many pounds of force act on one square inch. In the US, psi is common for tires, gas systems, and pressure ratings.
Use this conversion:
Because the value is tiny, results often show in scientific notation.
Use this conversion:
This is useful when you have psi and need vacuum units.
No. They are related but not the same.
mTorr is used for low pressures, often in vacuum work. Psi is a larger unit used for everyday pressure levels. Since 1 psi equals about 51.7 million mTorr, converting mTorr to psi gives a very small decimal.
mTorr shows up in vacuum systems such as:
These systems often operate in ranges like 1 mTorr to 1,000 mTorr, which are far below normal air pressure.
Here are a few common values:
1 psi = 51,714,932.6 mTorr.
This large number is normal because psi is much larger than mTorr.
760,000 mTorr equals 760 Torr, which is close to standard atmospheric pressure.
This matches the common value of about 14.7 psi for sea-level air pressure.
No. The conversion is a fixed unit change. Temperature can change the actual pressure in a system, but it doesn’t change how mTorr and psi relate as units.
mTorr is almost always absolute pressure (referenced to a perfect vacuum). Psi may be shown as:
If you mix them up, the numbers won’t match your system. For vacuum work, psia is usually the right match.
Only the scale changes:
If your value is in Torr, convert to mTorr by multiplying by 1,000 first (or use the Torr-to-psi factor directly).
The Calculate Box tool to convert millitorr to pounds per square inch uses the open source script Convert.js to convert units of measurement. To use this tool, simply type a millitorr value in the box and have it instantly converted to pounds per square inch.