Sustainability checks

Dew Point Calculator

Calculate the dew point temperature from air temperature and relative humidity using the Magnus formula. Use this Environment and sustainability tool to enter your numbers, review the result, and understand the key assumptions before making the next decision.

What you get
A focused calculator, clear explanation, common questions, and useful next tools.
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Result
Explanation
Common questions
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How this calculator works
The result depends on the numbers you enter and the assumptions shown below.

The dew point is the temperature at which air becomes saturated and condensation begins. Calculated using Magnus formula: Td = b×γ(T,RH) / (a−γ(T,RH)), where γ = ln(RH/100) + aT/(b+T).

Review the inputs carefully and treat the output as an estimate. For decisions involving money, taxes, health, law, or security, compare the result with trusted professional guidance when needed.

Frequently asked questions

What is a comfortable dew point?

Below 55°F (13°C) feels dry and comfortable. 55–65°F (13–18°C) is humid but tolerable. Above 65°F (18°C) feels muggy and oppressive.