How to determine aircrafts AGL from ADS-B

Use this free ADS-B to AGL calculator to estimate the Above Ground Level altitude of any aircraft broadcasting ADS-B data and gain more information about manned aircraft proximity to your drone. By combining METAR altimeter settings and your ground elevation, this tool makes it easy for drone pilots and aviation enthusiasts to convert barometric altitude to AGL. Whether you’re planning a safe drone flight or analyzing nearby traffic, this calculator gives you a fast and accurate reference.

ADS-B to AGL Calculator v3.0




Altimeter Setting: (not loaded)



Need your elevation manually? Find it here (in feet)




Disclaimer: This tool provides an estimated Above Ground Level (AGL) altitude based on publicly available ADS-B and METAR data. Accuracy may vary depending on local pressure, elevation precision, and system reporting delays. This calculator is for informational purposes only. No guarantees of accuracy are implied, and we assume no liability for use of this tool in operational decision-making.

🧠 What is ADS-B Altitude?

ADS-B broadcasts a barometric altitude, which is based on pressure settings from an altimeter. Secondly, the altimeter is set based on the airport the aircraft took off at. It doesn’t account for terrain or elevation, so it’s different from AGL (Above Ground Level) altitude, which is what drone pilots care about.

📡 Why Convert use ADS-B to AGL calculator?

Drone pilots flying under Part 107 and any other CFR rule are responsible for maintaining situational awareness and avoiding manned aircraft. Therefore, understanding AGL altitude from a barometric altitude is crucial for safety, especially when aircraft fly at low levels in shared airspace.

🔎 How Does This ADS-B to AGL Calculator Work?

This tool:

  • Uses METAR altimeter settings from the nearest airport
  • Accepts a barometric ADS-B altitude input
  • Uses your ground elevation (manually or auto-detected)
  • Outputs an estimated AGL value

For more geospatial workflows, see my post How I Turn Drone Data into Survey Deliverables. Come back to the blog for updates and behind-the-scenes insights. Also follow me on LinkedIn. If you need help with a project, I’m available, reach out and let’s talk.