Convert Newtons per Square Millimetre to Bar (N/mm2 to bar)

Formula

bar = N/mm² × 10

Derivation from SI units:

• 1 N/mm² = 1 N ÷ 10⁻⁶ m² = 10⁶ Pa = 1 MPa
• 1 bar = 10⁵ Pa (exact, by definition)
• 1 N/mm² = 1000000 Pa ÷ 100000 Pa per bar = 10 bar

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

Worked examples

1. A reading of 30 N/mm² converts to 300 bar.
   30 N/mm² × 10 = 300 bar
2. A value of 275 N/mm² is 2750 bar.
   275 N/mm² × 10 = 2750 bar

Where it's used

Newtons per Square Millimetre are used for steel yield and tensile strength (S355: 355 N/mm²), while bar appear in compressed air and pneumatics (6–8 bar). 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.
• 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, "bar".

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