Thermodynamics calculator

Dew Point Temperature Calculator

Use the Magnus approximation for common HVAC and weather checks.

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Calculator

Enter thermal values

Select units beside each input. Results update automatically.

Thermal

Result

About this calculator

How it works

Dew point is the temperature where moist air reaches saturation at constant water vapor content.

Formulas

Formulas used

Magnus approximation

Td = b gamma / (a - gamma)

gamma

gamma = aT/(b+T) + ln(RH/100)

Worked example

Example calculation

Dew point

25 C and 60% RH gives about 16.7 C

Guide

How to use this calculator

Enter the known temperature, pressure, energy, humidity, or material values.
Select units beside each input where unit menus are shown.
Use the highlighted result for screening and verify assumptions before design use.

Reference

What the results mean

Dew point

Temperature where condensation begins.

Humidity context

Higher relative humidity moves dew point closer to dry-bulb temperature.

Assumptions and limits

Before using the result

Calculations use simplified ideal relations or common approximations for quick engineering checks.
Real systems may require property tables, phase behavior, transient analysis, losses, and code or manufacturer data.
Use verified data and qualified engineering judgement for final design or safety-critical work.

FAQ

Dew Point Temperature Calculator questions

Are these results suitable for final thermodynamic design?

Use these tools for education, screening, and early checks. Final work should use verified properties, standards, operating limits, and qualified engineering review.

Why can real thermal systems differ from these calculations?

Real systems include losses, non-ideal properties, transient behavior, two-phase effects, humidity assumptions, heat leaks, and measurement uncertainty.

Can I use different units?

Yes. Select units beside inputs where menus are shown. Values are converted internally before solving.