To convert millitorr to millibars, multiply by 0.001333223684. That factor is the whole relationship: both units measure pressure, so the conversion is a proportion with no offset and no substance-specific constant.
The meteorologist’s unit — sea-level pressure averages 1013.25 mbar. One thousandth of a torr, the working unit of vacuum deposition.
Gauge versus absolute. A tyre gauge reading 32 psi means 32 psi above atmospheric, which is about 46.7 psi absolute. Converting the number is straightforward; remembering which zero it was measured from is where the mistakes happen. N/mm² and MPa are the same size, so a drawing quoting either is quoting the same stress. Two tables follow: rounded steps for quick lookup, and a set of real reference quantities converted into millibars, which is usually more useful than the bare number.
The formula
millitorr- The amount you are converting, in millitorr
0.00133322368421- The exact number of millibars in one millitorr
millibars- The converted result
How it works, step by step
- Enter the value in millitorr.
- It is multiplied by 0.00133322368421, the exact factor between the two units.
- The answer is shown in millibars, with the reverse conversion beneath it.
- Check the reference table if you want a figure of comparable size.
Worked examples
Blood pressure, systolic: 1.2e+05 mTorr in millibars
Take blood pressure, systolic, roughly 1.2e+05 mTorr. The conversion is a single multiplication — 1.2e+05 × 0.00133322 — giving 159.987 mbar. Because the relationship is proportional, doubling the input doubles the answer to 319.974 mbar.
A domestic water main: 3e+06 mTorr in millibars
Take a domestic water main, roughly 3e+06 mTorr. The conversion is a single multiplication — 3e+06 × 0.00133322 — giving 3999.67 mbar. Because the relationship is proportional, doubling the input doubles the answer to 7999.34 mbar.
How to read your score
Frequently asked questions
How many millibars are in one millitorr?
Exactly 0.00133322368421. Every figure on this page is that one number multiplied by your input, so the only rounding is at the display step.
What is the formula to convert millitorr to millibars?
millibars = millitorr × 0.00133322368421. Reversed, millitorr = millibars ÷ 0.00133322368421, which is the same as multiplying by 750.061682704.
Which is the bigger unit, the millitorr or the millibar?
The millibar. One millitorr is only 0.00133322 of a millibar, so it takes 750.062 millitorr to make one millibar.
What does this quantity actually measure?
Both units measure pressure. That is why a single factor is enough: there is no temperature offset and no material property involved, unlike conversions that cross between different quantities.
What is a millitorr?
One thousandth of a torr, the working unit of vacuum deposition.
What is a millibar?
The meteorologist’s unit — sea-level pressure averages 1013.25 mbar.
Why does my answer differ from another converter?
Almost always because the other tool rounded the factor before multiplying. This page keeps full double precision through the calculation and rounds only for display, and it prints the factor it used so you can see where any difference came from.
Is there a quick way to do mTorr to mbar in my head?
Plenty of people do this in their head: divide by 750 instead of using the exact factor 0.001333223684. At 100 that shortcut gives 0.13333333 millibars, off by 0.000011 millibars or about 0.01%. Fine for a rough estimate, not fine for anything you are cutting to size or dosing.
Millitorr to millibars reference tables
| Millitorr | Millibars |
|---|---|
| 0.5 mTorr | 0.000666612 mbar |
| 1 mTorr | 0.00133322 mbar |
| 2 mTorr | 0.00266645 mbar |
| 3 mTorr | 0.00399967 mbar |
| 5 mTorr | 0.00666612 mbar |
| 10 mTorr | 0.0133322 mbar |
| 20 mTorr | 0.0266645 mbar |
| 25 mTorr | 0.0333306 mbar |
| 50 mTorr | 0.0666612 mbar |
| 75 mTorr | 0.0999918 mbar |
| 100 mTorr | 0.133322 mbar |
| 250 mTorr | 0.333306 mbar |
| 500 mTorr | 0.666612 mbar |
| 1000 mTorr | 1.33322 mbar |
| 5000 mTorr | 6.66612 mbar |
Exact factor: 1 millitorr = 0.00133322368421 millibars.
| Quantity | mTorr | mbar |
|---|---|---|
| Sea-level air | 7.6e+05 mTorr | 1013 mbar |
| A car tyre | 1.655e+06 mTorr | 2206 mbar |
| Blood pressure, systolic | 1.2e+05 mTorr | 160 mbar |
| A bicycle tyre | 4.654e+06 mTorr | 6205 mbar |
| A domestic water main | 3e+06 mTorr | 4000 mbar |
| A steam boiler | 7.501e+06 mTorr | 1e+04 mbar |
Published reference values, converted with the same factor this page uses.