Convert Megapascals to Centimeters of Water (MPa to cmH2O)

Formula

cmH₂O = MPa × 10197.16212978

Derivation from SI units:

• 1 MPa = 10⁶ Pa = 1 N/mm²
• 1 cmH₂O = 1000 kg/m³ × 9.80665 m/s² × 0.01 m = 98.0665 Pa
• 1 MPa = 1000000 Pa ÷ 98.0665 Pa per cmH₂O = 10197.16212978 cmH₂O

Both units are defined exactly, so the factor is exact. Megapascal definition: megapascal; Centimeter of Water definition: centimeter of water.

Worked examples

1. A reading of 2 MPa converts to 20394.32426 cmH₂O.
   2 MPa × 10197.16213 = 20394.32426 cmH₂O
2. A value of 30 MPa is 305914.8639 cmH₂O.
   30 MPa × 10197.16213 = 305914.8639 cmH₂O

Where it's used

Megapascals are used for concrete compressive strength (typically 20–50 MPa), while centimeters of water appear in mechanical ventilation (PEEP 5–10 cmH₂O, plateau pressure under 30 cmH₂O). Both measure pressure, stress and differential pressure (force per unit area), so the conversion is a fixed factor.

Megapascal 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 7, SI prefixes.
• 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)".

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