Convert Kilograms-force per Square Millimetre to Gigapascals

Formula

GPa = kgf/mm² × 0.00980665

or GPa = kgf/mm² ÷ 101.9716212978

Derivation from SI units:

• 1 kgf/mm² = 9.80665 N ÷ 1 mm² = 9.80665 MPa (exact)
• 1 GPa = 10⁹ Pa = 1000 MPa = 1 kN/mm²
• 1 kgf/mm² = 9806650 Pa ÷ 1000000000 Pa per GPa = 0.00980665 GPa

Both units are defined exactly, so the factor is exact. Kilogram-force per Square Millimetre definition: kilogram-force per square millimetre; Gigapascal definition: gigapascal.

Worked examples

1. A reading of 24 kgf/mm² converts to 0.2353596 GPa.
   24 kgf/mm² × 0.00980665 = 0.2353596 GPa
2. A value of 50 kgf/mm² is 0.4903325 GPa.
   50 kgf/mm² × 0.00980665 = 0.4903325 GPa

Where it's used

Kilograms-force per Square Millimetre are used for tensile strength in older JIS and GB steel standards, while gigapascals appear in young's modulus and shear modulus of metals, ceramics and composites. Both measure pressure, stress and differential pressure (force per unit area), so the conversion is a fixed factor.

Kilogram-force per Square Millimetre 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, "kilogram-force per square millimeter".
• The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 7, SI prefixes.

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