Precise astrology
calculators
Most astrology calculators round to the month, and nobody seems to mind. These search a real ephemeris for the exact instant, right here in your browser.
- No sign-up
- Nothing stored
- MIT astronomy-engine
Ten calculators
Each one runs the astronomy in your browser, then tells you, separately, what astrologers make of the result.
Big 3
Sun, Moon and rising sign together, each to the exact degree, from your birth date, time and city.
Saturn Return
The dates of your first, second and third Saturn returns, with every retrograde pass.
Solar Return
The minute the Sun gets back to its natal degree each year, in your birth or current time zone.
Rising Sign
Your ascendant and big three from an exact birth time and place. No time, no guess.
Black Moon Lilith
Your Mean Black Moon Lilith by sign, exact degree and house. Most sites round this one.
Birth Moon Phase
The Moon's phase and sign at the moment you were born, and what astrologers say that pairing means.
Moon Phase Compatibility
Two birth Moon phases compared, for how your emotional rhythms fit or grate.
Natal Retrograde
Which of the 8 planets were retrograde when you were born, from the date alone, and how common each one is.
Mercury Retrograde
Station dates for every Mercury retrograde and shadow period, searched from the ephemeris to the minute.
Cycle Lab
Every eclipse and planetary station near any zodiac degree, 1900–2100, beside the baseline that says whether it means anything.
Reference tables
No form on these. They are the dates themselves, twenty pages of them, from the same ephemeris the calculators use.
Why trust these numbers
Astronomy first, astrology second
Every calculator I tried rounded Saturn to the month. This one computes each moment from the actual positions of the Sun, Moon and planets, then searches for the exact instant your event happens, and the methodology page shows how that is tested.
A real ephemeris
Positions come from astronomy-engine (MIT), tested against JPL Horizons. No scraped tables and no date arithmetic.
The exact instant
Each tool searches numerically for the moment a planet hits its target, so returns and stations come out as a date and a time.
Nothing leaves your browser
Everything runs on your device. Your birth data is never uploaded, stored or attached to an account.
The working is shown
Every tool says what it assumes and where the birth time matters, and the methodology page has the rest.
Common questions
Short answers to the things people ask before they type in a birthday.
How accurate are these calculators?
To well under an arcminute, which is finer than astrology can use. The positions come from astronomy-engine, an MIT-licensed ephemeris of the same class professional software runs, and each tool searches for the exact instant a planet reaches its target rather than rounding to the month. The methodology page lists the tests.
What's an ephemeris?
A table of where the Sun, Moon and planets are at any given moment. The old ones were printed books; the one here is a library, astronomy-engine, that computes the positions on the fly in your browser. The calculators ask it where a planet is, then search it for the exact instant the planet reaches the point that matters to you.
Do I need my exact birth time?
Depends on the tool. The rising sign needs the real time and the city, because the ascendant moves about one degree every four minutes. Saturn return, solar return and the Moon phase tools work from a birth date alone, and each result says where an exact time would sharpen it.
Is any of my birth data stored or sent anywhere?
No. The calculations run in your browser and your birth details never leave it. There is no account and no server holding a copy. The site does carry ads, and the privacy page says what their cookies do and do not see.
Is it really free?
Yes. Nothing to sign up for and nothing behind a paywall. The maths runs on your device, so there is no server bill to pass on to you. Ads pay for the domain.