Newtons per Square Millimetre to Gigapascals (N/mm2 to GPa)

Formula

GPa = N/mm² ÷ 1000

Derivation from SI units:

• 1 N/mm² = 1 N ÷ 10⁻⁶ m² = 10⁶ Pa = 1 MPa
• 1 GPa = 10⁹ Pa = 1000 MPa = 1 kN/mm²
• 1 N/mm² = 1000000 Pa ÷ 1000000000 Pa per GPa = 0.001 GPa

Both units are defined exactly, so the factor is exact. Newton per Square Millimetre definition: newton per square millimetre; Gigapascal definition: gigapascal.

Worked examples

1. A reading of 30 N/mm² converts to 0.03 GPa.
   30 N/mm² × 0.001 = 0.03 GPa
2. A value of 275 N/mm² is 0.275 GPa.
   275 N/mm² × 0.001 = 0.275 GPa

Where it's used

Newtons per Square Millimetre are used for steel yield and tensile strength (S355: 355 N/mm²), 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.

Newton per Square Millimetre 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 4, coherent derived units with special names.
• 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.