Everyday

Dew Point Calculator — Humidity Temperature Online

Calculate the dew point temperature from air temperature and relative humidity using the Magnus formula. Shows comfort level.

How to use this calculator

👉 Fill in the boxes below and your answer appears instantly — no maths needed, we do it all for you! 🎉

👶

In plain English — what does this do?

📏 Some countries say ‘30 degrees’ and others say ‘86 degrees’ for the same weather! Some say ‘5 km’, others say ‘3 miles’. This tool swaps between them instantly so you always know what it means.

📌 Direct Answer & Summary

The dew point is the temperature at which air becomes saturated with moisture and water vapor begins to condense. It's a direct measure of atmospheric moisture content and a reliable indicator of how humid and uncomfortable the air feels.

What is Dew Point Calculator — Humidity Temperature Online?

The dew point is the temperature at which air becomes saturated with moisture and water vapor begins to condense. It's a direct measure of atmospheric moisture content and a reliable indicator of how humid and uncomfortable the air feels.

How to use it

  1. 1️⃣ Select your temperature unit (°C or °F).
  2. 2️⃣ Enter the current air temperature.
  3. 3️⃣ Enter the relative humidity percentage.
  4. 4️⃣ Click Calculate to get the dew point and comfort level.
  5. 5️⃣ Dew points above 60°F (16°C) start to feel uncomfortable for most people.

Formula

Magnus formula: Td = (243.04 × γ) / (17.625 − γ), where γ = ln(RH/100) + 17.625×T / (243.04 + T), T in °C.

💡 See it in action — a real example

At 30°C and 70% humidity: γ = ln(0.70) + 17.625×30/(243.04+30) = −0.3567 + 1.9347 = 1.578. Td = (243.04 × 1.578) / (17.625 − 1.578) ≈ 23.9°C (75°F) — oppressive.

❓ Common questions

What is a comfortable dew point?
Dew points below 55°F (13°C) feel dry and comfortable. Between 55–65°F it starts feeling humid. Above 65°F feels sticky; above 75°F is oppressive.
How is dew point different from humidity?
Relative humidity changes with temperature but dew point stays constant. Dew point is a more reliable indicator of absolute moisture in the air.
What does 100% humidity mean?
At 100% relative humidity, the air temperature equals the dew point. Condensation (fog, dew) forms on surfaces.
Can the dew point be higher than the air temperature?
No. The dew point is always equal to or lower than the air temperature. When they're equal, relative humidity is 100%.
Why does the dew point matter for health?
High dew points reduce the body's ability to cool itself by sweating. Combined with high temperatures, this raises heat stress and risk of heat illness.
🧩

Embed Dew Point Calculator — Humidity Temperature Online

Copy & paste this snippet into your website HTML, blog post, or WordPress site to display this interactive calculator widget:

Widget Attribution Link: allcalcihub.com