Convert Centimeters of Water to kgf/mm²

Formula

kgf/mm² = cmH₂O ÷ 100000

Derivation from SI units:

• 1 cmH₂O = 1000 kg/m³ × 9.80665 m/s² × 0.01 m = 98.0665 Pa
• 1 kgf/mm² = 9.80665 N ÷ 1 mm² = 9.80665 MPa (exact)
• 1 cmH₂O = 98.0665 Pa ÷ 9806650 Pa per kgf/mm² = 0.00001 kgf/mm²

Both units are defined exactly, so the factor is exact. Centimeter of Water definition: centimeter of water; Kilogram-force per Square Millimetre definition: kilogram-force per square millimetre.

Worked examples

1. A reading of 6 cmH₂O converts to 0.00006 kgf/mm².
   6 cmH₂O × 0.00001 = 0.00006 kgf/mm²
2. A value of 30 cmH₂O is 0.0003 kgf/mm².
   30 cmH₂O × 0.00001 = 0.0003 kgf/mm²

Where it's used

Centimeters of Water are used for mechanical ventilation (PEEP 5–10 cmH₂O, plateau pressure under 30 cmH₂O), while kilograms-force per square millimetre appear in tensile strength in older JIS and GB steel standards. Both measure pressure, stress and differential pressure (force per unit area), so the conversion is a fixed factor.

Centimeter of Water 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, "centimeter of water, conventional (cmH2O)".
• 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".

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