Millimeters of Mercury to Inches of Mercury Converter
1 millimeter of mercury ≈ 0.0393700787 inches of mercury
Almost identical to the torr, but defined separately. This uses conventional mmHg, not a temperature-specific mercury-column realization.
1 millimeter of mercury equals 0.0393701 inches of mercury
How to convert millimeters of mercury to inches of mercury
Unit conversion preserves the pressure reference. Gauge pressure and absolute pressure are different readings; changing between them also needs the ambient pressure. Mercury and water-column units use the conventions stated in their unit notes.
inHg = mmHg × 0.03937007874One millimeter of mercury is 0.03937007874 inches of mercury, so a single multiplication converts any value.
0.393701 inHg ≈ 10 × 0.03937007874Almost identical to the torr, but defined separately. This uses conventional mmHg, not a temperature-specific mercury-column realization.
Millimeters of mercury to inches of mercury conversion table
Common values in millimeters of mercury, converted to inches of mercury.
| Millimeters of mercury (mmHg) | Inches of mercury (inHg) |
|---|---|
| 1 | 0.039370079 |
| 2 | 0.078740157 |
| 3 | 0.11811024 |
| 4 | 0.15748031 |
| 5 | 0.19685039 |
| 10 | 0.39370079 |
| 20 | 0.78740157 |
| 25 | 0.98425197 |
| 50 | 1.9685039 |
| 100 | 3.9370079 |
| 250 | 9.8425197 |
| 500 | 19.685039 |
| 1,000 | 39.370079 |
About these units
millimeter of mercurymmHg
The conventional millimetre of mercury: 133.3224 Pa, following the NIST SP 811 convention.
Reference: NIST Special Publication 811.
inch of mercuryinHg
Exactly 25.4 mmHg. The US aviation and weather-report pressure unit.
Sources and precision
Table results are rounded to 8 significant digits; formula constants may be rounded to 10. Worked example answers use 6 significant digits. The converter starts at 6 significant digits and lets you change display precision. Calculations use the stored factors without intermediate rounding. Exact unit definitions do not make an input measurement more precise; conventional and measured factors follow the assumptions stated here.