Light Pollution Calculator

Estimate naked-eye and telescope limiting magnitude and SQM reading based on Bortle class, altitude, and moon phase.

Bortle Class (1-9)

Altitude (ft)

Moon Phase (%)

Tab to move between fields

Naked-Eye Limit

5.6 mag

Telescope Limit (8")

12.9 mag

SQM Reading20.49 mag/arcsec²

How to Use This Calculator

Enter Bortle Class (1-9), Altitude (ft), and Moon Phase (%).
Review Naked-Eye Limit (mag) and Telescope Limit (8 (mag).
Use SQM Reading (mag/arcsec²) to inform your decision.
Use the chart to visualize the results and explore different scenarios by adjusting inputs.

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