Ephemeris Calculator
Tropical longitudes, declination and RA for the Sun, Moon and planets — fully offline
Uses astronomy-engine (Jean Meeus / VSOP-class series) entirely in the tab. Enter a local time, timezone and coordinates to get longitude, latitude, RA, declination and retrograde flags. Nothing is uploaded.
About this tool
Calculate tropical zodiac degrees, right ascension and declination for the Sun, Moon and planets in your browser. Download JSON or CSV. Ephemeris Calculator runs in the browser on DevTools. There is no signup, and your input stays on this device unless the tool explicitly performs a live network lookup.
What this tool does not do
- Ephemeris Calculator is a free in-browser utility, not a hosted API. It does not keep server-side history and is not a substitute for production verification in your own stack.
How do I use this tool?
How do I use Ephemeris Calculator?
Open Ephemeris Calculator, enter or paste your input, and copy the result. The page works without an account.
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