Convert ksi to Millibars (ksi to mbar)

Formula

mbar = ksi × 68947.57293168

Derivation from SI units:

• 1 ksi = 1000 psi = 1 kip/in² = 6.894757293168 MPa
• 1 mbar = 10⁻³ bar = 100 Pa = 1 hPa
• 1 ksi = 6894757.293168 Pa ÷ 100 Pa per mbar = 68947.57293168 mbar

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

Worked examples

1. A reading of 20 ksi converts to 1378951.459 mbar.
   20 ksi × 68947.57293 = 1378951.459 mbar
2. A value of 65 ksi is 4481592.241 mbar.
   65 ksi × 68947.57293 = 4481592.241 mbar

Where it's used

ksi are used for yield and tensile strength in ASTM and ASME material specifications, 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.

ksi 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, "kip per square inch (ksi)".
• 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.