Convert Inches of Water to Torr

Convert Inches of Water (inH₂O) to Torr (Torr) instantly and accurately.

Inches of Water (inH₂O)
Torr (Torr)

Conversion Formula

Torr = inH₂O × 1.86832047

About Inches of Water

One inch of water column (inH₂O or in WC) = pressure from 1 inch of fresh water at standard gravity ≈ 249.09 Pa. The standard unit for low-pressure measurement in US HVAC and plumbing: ductwork static pressure, fan performance, filter ratings, and gas appliance manifold pressures are all specified in inches WC. Household natural gas supply pressure is typically 7 in WC (0.25 psi). Blower door tests for building air-tightness use 50 Pa ≈ 0.2 in WC test pressure. 1 inH₂O = 249.089 Pa.

About Torr

The torr is defined as exactly 1/760 of a standard atmosphere ≈ 133.322 Pa - effectively replacing mmHg with an exact definition. Named after Evangelista Torricelli (1608-1647), inventor of the barometer. Vacuum science universally uses torr: rough vacuum 760-1 torr; medium vacuum 1-10⁻³ torr; high vacuum 10⁻³-10⁻⁷ torr; ultra-high vacuum below 10⁻⁹ torr. UHV systems for surface science, particle accelerator beam tubes, and space simulation chambers reach 10⁻¹¹-10⁻¹² torr. 1 torr = 133.322 Pa.

Quick Reference Table

Inches of Water (inH₂O)Torr (Torr)
1 inH₂O1.86832 Torr
2 inH₂O3.73664 Torr
5 inH₂O9.3416 Torr
10 inH₂O18.6832 Torr
25 inH₂O46.708 Torr
50 inH₂O93.416 Torr
100 inH₂O186.832 Torr

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