Compare calculators

Both calculators run independently — change the inputs on either side to compare results.

Dew Point Calculator

Estimate the temperature at which air becomes saturated and dew or frost begins to form, using an approximation of the Magnus formula. Useful for assessing humidity comfort, condensation risk, and HVAC sizing.

Air Temperature (°F)

Relative Humidity (%)

Fill in the required fields to see your result.

Climate

Evapotranspiration Calculator

Estimate monthly potential evapotranspiration (PET) from average temperature, daylight hours, and days in the month using a simplified Thornthwaite-style formula. Returns millimetres of water lost per month.

Average Temperature (°C)

Daylight Hours (hours)

Days in Month (days)

Fill in the required fields to see your result.

Key differences

	Dew Point Calculator	Evapotranspiration Calculator
Category	Climate	Climate
Inputs required	2	3
Result	Dew Point Temperature (°F)	Potential Evapotranspiration (mm/month)
What it does	Estimate the temperature at which air becomes saturated and dew or frost begins to form, using an approximation of the Magnus formula. Useful for assessing humidity comfort, condensation risk, and HVAC sizing.	Estimate monthly potential evapotranspiration (PET) from average temperature, daylight hours, and days in the month using a simplified Thornthwaite-style formula. Returns millimetres of water lost per month.