Duct Pressure Unit Converter (Pa / in wg / mm wg)
Pascal ↔ inches & mm of water gauge — manometer language across continents.
Indian sites speak mmWC, US fan tables in wg, EU datasheets Pa. 25 mmWC ≈ 1 in wg ≈ 250 Pa — a coincidence worth memorizing.
Formula
Duct Pressure Unit Converter (Pa / in wg / mm wg) is a free pa to inwg for HVAC designers, technicians and energy auditors — instant, accurate and 100% client-side, with the governing formula and reference shown next to the result so the number can be defended, not just quoted.
About Duct Pressure Unit Converter (Pa / in wg / mm wg)
Pascal ↔ inches & mm of water gauge — manometer language across continents. The calculation implements 1 in wg = 249 Pa; 1 mm wg = 9.81 Pa (NIST SP 811). Indian sites speak mmWC, US fan tables in wg, EU datasheets Pa. 25 mmWC ≈ 1 in wg ≈ 250 Pa — a coincidence worth memorizing.
How to use Duct Pressure Unit Converter (Pa / in wg / mm wg)
- 1Enter Pressure in Pa.
- 2Read Inches water gauge, mm water gauge (mmWC), PSI instantly — no submit button needed.
- 3Need US units? Flip the SI/Imperial toggle and every field converts.
Why use Duct Pressure Unit Converter (Pa / in wg / mm wg)?
- ✓Implements the standard formula — 1 in wg = 249 Pa; 1 mm wg = 9.81 Pa
- ✓Reference cited on-page: NIST SP 811
- ✓One-click SI ⇄ Imperial toggle — values convert in place, physics stays in SI
- ✓Live worked example: the substitution recomputes from your numbers
- ✓Runs entirely in your browser — nothing uploaded, free forever
Frequently asked questions
What formula does the Duct Pressure Unit Converter (Pa / in wg / mm wg) use?+
It computes 1 in wg = 249 Pa; 1 mm wg = 9.81 Pa, per NIST SP 811. The formula is displayed under the result along with a worked example substituted with your own inputs.
What should I keep in mind when using this calculator?+
Indian sites speak mmWC, US fan tables in wg, EU datasheets Pa. 25 mmWC ≈ 1 in wg ≈ 250 Pa — a coincidence worth memorizing.
Is this based on ASHRAE methods?+
The calculations follow the standard ASHRAE/ISHRAE formulations cited under the result, simplified where industry practice does the same. For permit-grade design, confirm with the full code procedure.
Is the Duct Pressure Unit Converter (Pa / in wg / mm wg) free to use?+
Yes — completely free, no sign-up, no limits. It runs client-side in your browser, so inputs stay private and results are instant even on slow connections.
Related Engineering tools
Reynolds Number Calculator
Compute Re from density, velocity, pipe diameter and viscosity — with instant laminar/turbulent classification.
● LiveLaminar vs Turbulent Flow Classifier
Classify hydraulic-oil or process-fluid flow regime from kinematic viscosity, line velocity and tube bore.
● LiveBernoulli Equation Solver
Solve downstream pressure between two points from velocities, elevations and fluid density (ideal, lossless).
● Live