Convert Kilopascals to Millibars

Formula

mbar = kPa × 10

Derivation from SI units:

• 1 kPa = 10³ Pa
• 1 mbar = 10⁻³ bar = 100 Pa = 1 hPa
• 1 kPa = 1000 Pa ÷ 100 Pa per mbar = 10 mbar

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

Worked examples

1. A reading of 20 kPa converts to 200 mbar.
   20 kPa × 10 = 200 mbar
2. A value of 300 kPa is 3000 mbar.
   300 kPa × 10 = 3000 mbar

Where it's used

Kilopascals are used for tyre pressure outside the United States (about 200–250 kPa for cars), 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.

Kilopascal to other pressure units

Frequently asked questions

Sources

• The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 7, SI prefixes.
• 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.