About Moon Sign Calculator

This site exists for one job — a moon sign calculator that gives a clear answer quickly and shows how it was reached.

How we test the calculations

Every release of the moon sign calculator is checked by an automated test suite of 123 checks in a real browser — normal values, edge cases and invalid input — and on desktop and phone screen sizes before it goes live.

References

The formulas and reference values in the guides follow published standards and primary sources, linked where they are used: eclipse.gsfc.nasa.gov, developer.mozilla.org.

How we write

The editorial team writes for one reader: someone who needs a reliable answer now. That means worked examples, units spelled out, honest limits and no sponsored recommendations.

Updates and corrections

Published October 8, 2026, last reviewed October 12, 2026. Corrections are welcome via the contact page; confirmed fixes go out with the next update.

Advertising

The tool is free to use. The site is funded by advertising, which never influences results or explanations.

— Moon Sign Calculator editorial team