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Water Vapor Pressure — H₂O Saturation

Saturation pressure vs. temperature · Absolute · HVAC · Boilers · Process engineering

Buck (1981) · ±0.05% Magnus (ice) · ±0.1% −30…200 °C Pa · mbar · bar · kPa · atm
Temperature input
Temperature T 25 °C
−30050100150200°C
°C
Equation used
About this tool
Saturation vapor pressure of pure water computed with the Buck (1981) equation over liquid and the Magnus-Tetens formula over ice. Used in HVAC design, boiler sizing, distillation, and psychrometrics.
Saturation vapor pressure p° (absolute)
Pa
mbar kPa bar atm
Pascal (abs.)
Pa
Millibar (abs.)
mbar
Bar (abs.)
bar
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T [°C]PambarkPabaratm
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p°(H₂O) liquid
p°(H₂O) ice
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