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Pressure
InHg to MmHg
Convert inHg (inHg) to mmHg (mmHg). Type a value below to see the result update instantly. Reference table and formula included.
Calculator
1 inHg = 25.4001 mmHg
InHg to MmHg Conversion Table
Common values, ready to copy:
| inHg | mmHg |
|---|---|
| 1 inHg | 25.4001 mmHg |
| 2 inHg | 50.8002 mmHg |
| 5 inHg | 127 mmHg |
| 10 inHg | 254 mmHg |
| 25 inHg | 635 mmHg |
| 50 inHg | 1270 mmHg |
| 100 inHg | 2540.01 mmHg |
| 1,000 inHg | 25400.08 mmHg |
Formula
mmHg = inHg × 2.54000840e+1
Pressure is force per area. 1 atm = 101.325 kPa = 14.696 psi = 760 mmHg. Bar is a metric working unit close to atmospheric pressure (1 bar = 100 kPa).
About InHg and MmHg
InHg (inHg): Inches of mercury, the imperial equivalent of mmHg; 1 inHg = 25.4 mmHg by definition. Common uses: US weather reports (atmospheric pressure in inches of mercury, standard sea-level pressure ≈ 29.92 inHg), US aviation altimeter settings, and some US vacuum-system contexts.
MmHg (mmHg): Millimeters of mercury; the pressure exerted by a column of mercury that height; a torr is essentially identical (1 mmHg ≈ 1 torr to within 1 part in 7 million). Common uses: Blood pressure (systolic over diastolic, in mmHg), vacuum systems, barometric pressure in some medical and scientific contexts.
How the conversion works
Pressure is force per area. 1 atm = 101.325 kPa = 14.696 psi = 760 mmHg. Bar is a metric working unit close to atmospheric pressure (1 bar = 100 kPa).
The exact relationship is mmHg = inHg × 2.54000840e+1, which the calculator at the top of this page applies in both directions. Type into either field and the other updates immediately.
When this conversion matters
Converting between inHg and mmHg comes up wherever pressure measurements move between systems — from one country's conventions to another's, from a scientific reference to a practical specification, or from one industry's working unit to another's. The calculator and reference table above cover the everyday range; for unusual values you can type any number into either field.