Interactive psychrometric chart for moist air in SI units. Click the chart or enter values to calculate all thermodynamic air properties. Includes two-point process analysis for HVAC load calculations.
| Dry Bulb Temperature | -°C |
| Wet Bulb Temperature | -°C |
| Dew Point | -°C |
| Relative Humidity | -% |
| Humidity Ratio | -g/kg |
| Enthalpy | -kJ/kgda |
| Specific Volume | -m³/kgda |
| Density | -kg/m³ |
| Vapour Pressure | -Pa |
| Saturation Pressure | -Pa |
This psychrometric calculator helps HVAC engineers, mechanical designers, and building services professionals determine moist air properties from any two known inputs. Enter dry bulb temperature with either relative humidity, wet bulb temperature, or dew point temperature, and the calculator will compute all remaining psychrometric properties including enthalpy, humidity ratio, specific volume, and vapour pressure. The interactive psychrometric chart plots your air state in real time.
The calculator uses the Buck equation for saturation pressure (accurate to within 0.02%) and follows standard ASHRAE psychrometric relationships at the specified atmospheric pressure. You can also use the process analysis mode to evaluate common HVAC processes such as sensible heating, sensible cooling, cooling with dehumidification, and adiabatic mixing of two airstreams. This is useful for verifying coil performance, checking supply air conditions, and sizing equipment.
This tool provides accurate results for standard HVAC temperature ranges at near-sea-level pressures. For high-altitude projects, adjust the atmospheric pressure input accordingly. Final equipment selection and system design should be verified against manufacturer data and comply with relevant standards including AS 1668.2 for ventilation and AS/NZS 3823 for air conditioning performance. For complex air handling systems, consult a qualified mechanical engineer.