Convert Decibars to Inches of Mercury (dbar to inHg)

Formula

inHg = dbar × 2.952998330101

Derivation from SI units:

• 1 dbar = 10⁻¹ bar = 10⁴ Pa
• 1 inHg = 13 595.1 kg/m³ × 9.80665 m/s² × 0.0254 m = 3386.388640341 Pa
• 1 dbar = 10000 Pa ÷ 3386.388640341 Pa per inHg = 2.952998330101 inHg

Both units are defined exactly, so the factor is exact. Decibar definition: decibar; Inch of Mercury definition: inch of mercury.

Worked examples

1. A reading of 50 dbar converts to 147.6499165 inHg.
   50 dbar × 2.95299833 = 147.6499165 inHg
2. A value of 1000 dbar is 2952.99833 inHg.
   1000 dbar × 2.95299833 = 2952.99833 inHg

Where it's used

Decibars are used for oceanography: CTD instruments report sea pressure in dbar, while inches of mercury appear in aircraft altimeter settings (standard 29.92 inHg). Both measure pressure, stress and differential pressure (force per unit area), so the conversion is a fixed factor.

Decibar 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, "bar", with SI prefix deci (10⁻¹).
• 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, "inch of mercury, conventional (inHg)".

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