Convert Millimeters of Mercury to Megapascals (mmHg to MPa)

Formula

MPa = mmHg × 0.000133322387415

or MPa = mmHg ÷ 7500.615758457

Derivation from SI units:

• 1 mmHg = 13 595.1 kg/m³ × 9.80665 m/s² × 0.001 m = 133.322387415 Pa
• 1 MPa = 10⁶ Pa = 1 N/mm²
• 1 mmHg = 133.322387415 Pa ÷ 1000000 Pa per MPa = 0.000133322387415 MPa

Both units are defined exactly, so the factor is exact. Millimeter of Mercury definition: millimeter of mercury; Megapascal definition: megapascal.

Worked examples

1. A reading of 80 mmHg converts to 0.01066579099 MPa.
   80 mmHg × 0.0001333223874 = 0.01066579099 MPa
2. A value of 160 mmHg is 0.02133158199 MPa.
   160 mmHg × 0.0001333223874 = 0.02133158199 MPa

Where it's used

Millimeters of Mercury are used for blood pressure (e.g. 120/80 mmHg), while megapascals appear in concrete compressive strength (typically 20–50 MPa). Both measure pressure, stress and differential pressure (force per unit area), so the conversion is a fixed factor.

Millimeter of Mercury to other pressure units

Frequently asked questions

Sources

• Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "millimeter of mercury, conventional (mmHg)".
• The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 7, SI prefixes.

Last reviewed: 2026-10-15. Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.