Weather calculator
Calculate Dew Point or Relative Humidity
Dew point
65°F (18°C)
How it feels
Slightly sticky
Estimated cloud base
3,400 ft (1,050 m)
How the dew point calculator works
The dew point is the temperature at which air becomes saturated and water starts to condense. It works in both directions here: enter temperature and relative humidity to get the dew point, or temperature and dew point to get the relative humidity. It also estimates the height of the cloud base for rising air.
Magnus formula (Alduchov and Eskridge constants) Td = 243.04·γ / (17.625 − γ) Cloud base ≈ 125 m per °C of spreadQuick tips
- A dew point above 65°F (18°C) feels muggy whatever the relative humidity says.
- A small spread means fog or dew. When temperature and dew point are within 2-3°F (1-2°C), expect condensation on cars and grass.
- The cloud base estimate is for convective clouds. It works best for fair-weather cumulus on a sunny afternoon.
How dew point feels
| Dew point | How it feels |
|---|---|
| Below 50°F (10°C) | Dry and comfortable |
| 50-60°F (10-16°C) | Pleasant |
| 60-65°F (16-18°C) | Slightly sticky |
| 65-70°F (18-21°C) | Muggy |
| 70-75°F (21-24°C) | Oppressive |
| Above 75°F (24°C) | Miserable |
Frequently asked questions
Can the dew point be higher than the temperature?
No. The dew point can equal the air temperature, which means 100% relative humidity and saturated air, but it cannot exceed it for long.
What is a comfortable dew point indoors?
Roughly 40-55°F (4-13°C). Below that the air feels dry and static builds up; above 60°F (16°C) indoor air starts to feel clammy.
How is the cloud base estimated?
Rising air cools faster than its dew point drops, and the two meet about 125 m (410 ft) higher for every 1°C of spread between temperature and dew point at the ground. It is an estimate for convective clouds, not for layered cloud.