Cloud Base Calculator
Estimate cloud-base height from temperature and dew point.
A QUICK WALKTHROUGH
How to use this tool
- Enter the values in the labeled units.
- Calculate and review the result.
- Change inputs to clear the previous result.
Method and limits
Rough weather teaching estimate: cloud base AGL = 125 × (T − Td) metres; T must be at least Td, both above −273.15 °C. Optional site elevation only adds to AGL to estimate MSL; it does not alter cloud formation. This is not a METAR observation or a flight decision aid.
Sources
https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/Balloon_Flying_Handbook_FAA-H-8083-11B/bfh_chapter_4.pdf · https://aviationweather.gov/help/data/
How is the result used?
For education only; never use this result for flight or navigation decisions. Inputs stay in this browser; nothing is sent.
GOOD TO KNOW
Common questions
How is the result used?
For education only; never use this result for flight or navigation decisions.