MMHG to TORR
Convert millimeters of mercury into torr for gauges, specs, hydraulic notes, and pressure reference checks.
Millimeters of mercury and torr are extremely close but not defined by exactly the same reference.
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MMHG to TORR Table
| Millimeters of Mercury | Torr |
|---|---|
| 1 | 1.000000142 |
| 5 | 5.00000071 |
| 10 | 10.00000142 |
| 25 | 25.00000355 |
| 50 | 50.0000071 |
| 100 | 100.0000142 |
| 250 | 250.0000355 |
| 500 | 500.000071 |
| 1,000 | 1,000.000142 |
| 2,500 | 2,500.000355 |
Popular Conversions
- 1 millimeters of mercury = 1.000000142 torr
- 5 millimeters of mercury = 5.00000071 torr
- 10 millimeters of mercury = 10.00000142 torr
- 25 millimeters of mercury = 25.00000355 torr
- 50 millimeters of mercury = 50.0000071 torr
- 100 millimeters of mercury = 100.0000142 torr
- 250 millimeters of mercury = 250.0000355 torr
- 500 millimeters of mercury = 500.000071 torr
What is Millimeters of Mercury and Torr?
Millimeters of Mercury
Definition: Millimeters of mercury express pressure using the height of a mercury column.
History/origin: The unit comes from classic barometers and medical manometers that measured pressure as a fluid height.
Current use: MmHg is used in blood pressure, vacuum work, laboratory pressure readings, and older engineering references.
Torr
Definition: A torr is a pressure unit equal to 1/760 of an atmosphere.
History/origin: It became a standard vacuum and laboratory unit closely tied to mercury-column measurements.
Current use: Torr is used in vacuum systems, scientific instruments, and pressure-control work.
Related Pressure Conversions
Pressure values are commonly translated across SI, customary, and fluid-column units in the same job.
| Related Conversion | Factor or Rule | Formula |
|---|---|---|
| mmHg to kPa | × 0.133322387 | kPa = mmHg × 0.133322387 |
| MPa to psi | × 145.037738 | psi = MPa × 145.037738 |
| Pa to kPa | ÷ 1,000 | kPa = Pa ÷ 1,000 |
| Pa to psi | × 0.000145037738 | psi = Pa × 0.000145037738 |
| psi to bar | × 0.068947573 | bar = psi × 0.068947573 |
| psi to mmHg | × 51.714933 | mmHg = psi × 51.714933 |
| psia to psig | minus atmosphere | psig = psia – atmospheric pressure |
| psig to psia | plus atmosphere | psia = psig + atmospheric pressure |
Typical Use Cases
Frequently Asked Questions
Q: Why do pressure pages like MMHG to TORR change the number so much?
A: Pressure units are sized very differently, so the same physical pressure can need a much larger or much smaller number after conversion. Millimeters of mercury and torr are extremely close but not defined by exactly the same reference.
Q: What does 1 millimeters of mercury become in torr?
A: 1 millimeters of mercury equals 1.000000142 torr, which is a helpful checkpoint for tire pressure, hydraulics, vacuum work, and process instrumentation.
Q: When should I keep the original pressure unit?
A: Keep it when the sensor, regulator, gauge, or specification you are reading already uses that unit. Convert only when the destination document or tool expects another scale.
Q: Why do some pressure answers become decimals while others become large integers?
A: That is simply the size difference between the unit systems involved. The physical pressure stays the same.
Q: How do I convert Torr back into Millimeters of Mercury?
A: mmHg = Torr ÷ 1.000000142. That reverse relationship is useful when the reading already starts in the target pressure unit.
Q: Is this exact or approximate?
A: The converter uses a standard approximation, so the value is a practical estimate rather than an exact universal constant.