Convert Inches of Mercury to ksi (inHg to ksi)

Formula

ksi = inHg × 0.0004911541474703

or ksi = inHg ÷ 2036.020677318

Derivation from SI units:

• 1 inHg = 13 595.1 kg/m³ × 9.80665 m/s² × 0.0254 m = 3386.388640341 Pa
• 1 ksi = 1000 psi = 1 kip/in² = 6.894757293168 MPa
• 1 inHg = 3386.388640341 Pa ÷ 6894757.293168 Pa per ksi = 0.0004911541474703 ksi

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

Worked examples

1. A reading of 15 inHg converts to 0.007367312212 ksi.
   15 inHg × 0.0004911541475 = 0.007367312212 ksi
2. A value of 29 inHg is 0.01424347028 ksi.
   29 inHg × 0.0004911541475 = 0.01424347028 ksi

Where it's used

Inches of Mercury are used for aircraft altimeter settings (standard 29.92 inHg), while ksi appear in yield and tensile strength in ASTM and ASME material specifications. Both measure pressure, stress and differential pressure (force per unit area), so the conversion is a fixed factor.

Inch 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, "inch of mercury, conventional (inHg)".
• 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)".

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