Convert Torr to Inches of Water
Convert Torr (Torr) to Inches of Water (inH₂O) instantly and accurately.
Conversion Formula
inH₂O = Torr × 0.5352400812
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.
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.
Quick Reference Table
| Torr (Torr) | Inches of Water (inH₂O) |
|---|---|
| 1 Torr | 0.53524 inH₂O |
| 2 Torr | 1.07048 inH₂O |
| 5 Torr | 2.6762 inH₂O |
| 10 Torr | 5.3524 inH₂O |
| 25 Torr | 13.381 inH₂O |
| 50 Torr | 26.762 inH₂O |
| 100 Torr | 53.524 inH₂O |