Convert Inches of Water (60 °F) to Centimeters of Water

Formula

cmH₂O = inH₂O (60 °F) × 2.537461824374

Derivation from SI units:

• 1 inH₂O (60 °F) ≈ 999.0 kg/m³ × 9.80665 m/s² × 0.0254 m ≈ 248.84 Pa
• 1 cmH₂O = 1000 kg/m³ × 9.80665 m/s² × 0.01 m = 98.0665 Pa
• 1 inH₂O (60 °F) = 248.84 Pa ÷ 98.0665 Pa per cmH₂O = 2.537461824374 cmH₂O

One unit is a measured value, so the factor is approximate. Inch of Water (60 °F) definition: inch of water (60 °F); Centimeter of Water definition: centimeter of water.

Worked examples

1. A reading of 0.5 inH₂O (60 °F) converts to 1.268730912 cmH₂O.
   0.5 inH₂O (60 °F) × 2.537461824 = 1.268730912 cmH₂O
2. A value of 7 inH₂O (60 °F) is 17.76223277 cmH₂O.
   7 inH₂O (60 °F) × 2.537461824 = 17.76223277 cmH₂O

Where it's used

Inches of Water (60 °F) are used for older US gas-industry and flow-meter references, 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.

Inch of Water (60 °F) 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, "inch of water (60 °F)".
• 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.