Convert Millimeters of Water to Gigapascals
Convert Millimeters of Water (mmH₂O) to Gigapascals (GPa) instantly and accurately.
Conversion Formula
GPa = mmH₂O × 9.806650000e-9
About Millimeters of Water
One millimetre of water column (mmH₂O) = pressure from 1 mm of fresh water at standard gravity = exactly 9.80665 Pa. Preferred for very low differential pressures in HVAC: ductwork static pressures, fan curves, filter resistance, and building pressurisation are in mm WC. Gas valve operating pressures are typically 0.5-3 mm WC; clean-room cascade differentials 12-25 mm WC. A domestic gas hob manifold operates at ~20 mm WC on natural gas. Also used in spirometer calibration and hospital oxygen delivery systems. 1 mmH₂O = 9.80665 Pa.
About Gigapascals
A gigapascal (GPa) = 10⁹ Pa = 10 kbar - the extreme-pressure unit for materials science and planetary physics. Bulk moduli: fused silica 72 GPa; iron 170 GPa; diamond 442 GPa (highest known). Earth's inner core: 330-360 GPa. Jupiter's core: ~40,000-70,000 GPa. NIF laser-shocked experiments create 100-100,000 GPa to reproduce planetary interior conditions. Metallic hydrogen is predicted to form above ~500 GPa and has been tentatively observed at 400-500 GPa in diamond anvil cells. 1 GPa = 10⁹ Pa = 10 kbar.
Quick Reference Table
| Millimeters of Water (mmH₂O) | Gigapascals (GPa) |
|---|---|
| 1 mmH₂O | 9.807 × 10-9 GPa |
| 2 mmH₂O | 1.961 × 10-8 GPa |
| 5 mmH₂O | 4.903 × 10-8 GPa |
| 10 mmH₂O | 9.807 × 10-8 GPa |
| 25 mmH₂O | 2.452 × 10-7 GPa |
| 50 mmH₂O | 4.903 × 10-7 GPa |
| 100 mmH₂O | 9.807 × 10-7 GPa |