Convert Torr to Centimeters of Water

Formula

cmH₂O = Torr × 1.359509806316

Derivation from SI units:

• 1 Torr = 101325/760 Pa = 133.3223684 Pa (1/760 of a standard atmosphere)
• 1 cmH₂O = 1000 kg/m³ × 9.80665 m/s² × 0.01 m = 98.0665 Pa
• 1 Torr = 133.3223684211 Pa ÷ 98.0665 Pa per cmH₂O = 1.359509806316 cmH₂O

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

Worked examples

1. A reading of 0.1 Torr converts to 0.1359509806 cmH₂O.
   0.1 Torr × 1.359509806 = 0.1359509806 cmH₂O
2. A value of 100 Torr is 135.9509806 cmH₂O.
   100 Torr × 1.359509806 = 135.9509806 cmH₂O

Where it's used

Torr are used for vacuum technology and vacuum gauges, 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.

Torr 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, "torr (Torr)".
• 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.