Astrology calculators, computed from the real sky.

What each calculator does

• Birth chart — the whole natal chart from date, time and place: every planet by sign, degree and house, plus the major aspects. Start here; every other tool reads from it.
• Zodiac sign — the Sun sign for a birth date, and on a cusp day both signs with the minute the Sun changed sign in the birthplace’s time zone.
• Rising sign — the Ascendant sign and degree, with the Midheaven and Placidus cusps from the same solve. Needs a birth time; it never guesses.
• Moon sign — the Moon’s sign, exact degree, house and your natal lunar phase. Falls back to noon if the time is unknown and warns when the result sits near a boundary.
• Stellium — every sign holding three or more of the ten planets, Sun to Pluto, and the whole-sign house it falls in when the birth time is known.
• Transits today — every aspect today’s planets make to your natal planets, with orb and whether each is applying or separating, and a reading for the strongest.
• Saturn return — every pass of transiting Saturn over your natal Saturn degree, first, second and third returns, with your age at each.
• Jupiter return — the date and age of every Jupiter return from birth to ninety, and which twelve-year cycle you are in now.
• Solar return — the instant the Sun returns to its natal degree in a chosen year, and the chart cast for that moment: return Ascendant, Sun house, planet table.
• Lunar return — your next lunar return (about every 27.3 days), with the return chart where a birth time allows one.
• Progressed Moon — the secondary-progressed Moon for today (day-for-a-year): sign, degree, natal house, when the current sign began and when the next one starts.
• Annual profection — this year’s profected house (age mod 12, plus one, counted from the Ascendant), its sign and time lord, with a twelve-year table.
• Eclipse impact — the next eighteen months of solar and lunar eclipses placed in your houses, flagging any natal planet or angle they conjoin, oppose or square within a tight orb.
• Moon phase — phase name, illumination, Sun–Moon angle, Moon sign and degree for any date from 1900 to 2100, plus the next new and full Moon.
• Void-of-course Moon — whether the Moon is void right now and every void window in the next seven days, shown in your own time zone.
• Retrograde stations — station retrograde and station direct dates, sign and degree for Mercury through Pluto, any year 1900 to 2100.
• Planetary hours — today’s sunrise and sunset for your location and the ruling planet of each of the 24 hours in Chaldean order.
• Free widgets — embed the Moon phase tool on your own site or newsletter: a live preview, a one-click snippet and install notes for WordPress and Squarespace. Computes in the reader’s browser, no account or API key.
• The sky right now — every planet’s current position, what is retrograde and the Moon’s phase, refreshed with the daily rebuild. No input needed.

How the calculations are done

Chart geometry comes from the Shymea engine, the same code path the app uses, so a result here matches what the app would show. The engine reads NASA JPL’s DE442 ephemeris through the Skyfield library, converts your birth time to Universal Time using the historical time-zone rules for the birth place, places every body on the tropical zodiac (the true ecliptic of date), and divides the sky into Placidus houses from your Ascendant. Two scans run in your browser instead, on purpose: the Saturn return search, because stepping ninety years of Saturn through the API would take hundreds of calls (it uses VSOP87 planetary theory, which agrees with the engine to the day for so slow a planet), and the moon phase calculator for dates other than today. Transits today compares your natal chart with a live sky table the engine refreshes every thirty minutes, using orbs of 8° for conjunctions and oppositions, 6° for trines and squares and 4° for sextiles, plus a degree for the Sun and Moon.

Free here, and what lives in the app

Everything on this page is free and needs no account: enter birth details, get the numbers, leave. Three things are deliberately not offered as web calculators. Synastry — laying two birth charts over each other — is done in the app, where both people consent before any chart detail is compared; the synastry guide explains how the reading works. Astrocartography and relocated charts are the app’s Navigate tab; the astrocartography page covers the method. Horary questions are likewise judged only in the app. Read about all of them on the app page.