The questions people actually type into a search box, answered plainly. Each one ends at the page that does the thing.
Your date of birth is enough. The Sun spends about a month in each sign, so only people born within a day or two of a boundary need to check the year — and the calculator does that from the real position rather than from a table of dates.
Open the calculator →Date, time and place. The Moon changes sign every two and a half days, so without a birth time it can land in either of two — the calculator uses noon as an estimate and says so. With a time it is exact, and you also get the house it falls in.
Open the calculator →The ascendant is the degree climbing over the eastern horizon at the minute you were born, so it needs the clock and the place — it moves about one degree every four minutes. Without a birth time it cannot be calculated at all, by us or by anyone.
Open the calculator →The date usually decides it: Venus stays in a sign for three to five weeks. Add a birth time and you also get the house, which says which part of life the way you love shows up in.
Open the calculator →From the date, in almost every case — Mars holds a sign for six weeks or more. The exception is a birthday within a day of a sign change, which the calculator resolves exactly.
Open the calculator →Houses come from the birth time and place, not from the date, so you need all three. The chart is cut into twelve slices from the horizon at your birth minute, and the Moon falls into one of them — that is the house. Without a time there are no houses to fall into.
Open the calculator →Yes, and most of it is right. The Sun, Mercury, Venus, Mars and the outer planets keep their sign across a whole day. What you lose is the ascendant, the houses, and an exact Moon — the Moon moves thirteen degrees a day, so a noon estimate can be up to six degrees out.
Read the article →Because two of the four things a chart is made of depend on it. The planets are where they are regardless, but the ascendant turns a full circle every twenty-four hours and the houses turn with it. Four minutes of clock is one degree of ascendant.
Read the article →No. A time rounded to the nearest five minutes moves the ascendant by about a degree, which changes the sign only if you were born near a boundary. Rounded to the hour is worse — the ascendant can be a whole sign off — but the planets and their aspects are unaffected.
The angle between where a planet is right now and a point in your birth chart. The chart is the fixed half — it is the sky at the minute you were born and it never moves again. Today’s sky is the moving half. A transit is the relationship between the two.
Open the calculator →A horoscope column knows only your Sun sign, so it assumes a Sun at the middle of that sign and works without houses — twelve readings for eight billion people. A transit reading uses the real degree of every planet in your chart, and the houses if you know your time.
Open the calculator →The fast ones daily. The Moon covers thirteen degrees a day, so its contacts last half a day; the Sun and Mercury hold for two or three, Venus and Mars for about a week. Jupiter through Pluto can sit on the same point for months, which is why they are named separately as climate rather than weather.
Read the article →The real position of the sky today at 12:00 UTC, computed with the same ephemeris as the calculators. Without a birth date it assumes a Sun at 15° of each sign and says so; add a date and it uses your actual Sun degree. It is not a recycled column.
Open the horoscope →Tropical, measured from the March equinox — the system used across almost all Western astrology. Sidereal longitudes differ by roughly twenty-four degrees today, which is often a whole sign. If you were expecting a sidereal chart, these positions will not match.
Read the article →Placidus by default, because it is what nearly every reading you will find assumes. Whole sign is available on a saved chart. On many charts nothing moves between them; when it does, it is usually one planet crossing one cusp.
Read the article →Planetary longitudes come from a VSOP87-class ephemeris and agree with professional software to well under a minute of arc. House cusps are computed by iteration rather than approximation and match reference values to four decimal places. Placidus is undefined inside the polar circles, and there the quadrants are trisected instead — the chart says when that happens.
Every calculator is free and needs no account. An account exists for one thing: keeping a chart, so the site can write a reading of the sky against it every day from the day you save it. The calculating never goes behind a sign-in.