bortle scale

Questions

What does bortle scale mean?

A nine-level numeric scale that measures the night sky's brightness of a particular location.

Where does bortle scale come from?

Named after John E. Bortle, who created the scale.

How to pronounce bortle scale

1. Open the pronunciation page — Open the Speakur entry for “bortle scale”.
2. Read the phonetic spelling — Read the IPA spelling () so you know which sounds to aim for.
3. Play the audio — Click Play to hear reference audio for “bortle scale”.
4. Repeat and practice — Say “bortle scale” aloud, matching stress and vowels until it feels natural.