Convert Decibars to Millibars

Formula

mbar = dbar × 100

Derivation from SI units:

• 1 dbar = 10⁻¹ bar = 10⁴ Pa
• 1 mbar = 10⁻³ bar = 100 Pa = 1 hPa
• 1 dbar = 10000 Pa ÷ 100 Pa per mbar = 100 mbar

Both units are defined exactly, so the factor is exact. Decibar definition: decibar; Millibar definition: millibar.

Worked examples

1. A reading of 50 dbar converts to 5000 mbar.
   50 dbar × 100 = 5000 mbar
2. A value of 1000 dbar is 100000 mbar.
   1000 dbar × 100 = 100000 mbar

Where it's used

Decibars are used for oceanography: CTD instruments report sea pressure in dbar, while millibars appear in weather maps and barometers (sea level ≈ 1013 mbar). 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, "millibar".

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