Birth Chart Calculator

What you'll get from this calculator

Type in your date, time, and place of birth (or search for your birth city and let the tool find the coordinates for you), and the calculator returns:

• Sun, Moon, and eight planet positions: which zodiac sign and house each one falls in, plus whether it's retrograde.
• Ascendant (rising sign) and Midheaven: the two most personal angles in a chart, both dependent on your exact birth time.
• Twelve house cusps: which sign begins each house, using the Placidus system by default (Whole Sign is also available).
• Major aspects: the angles between planets, such as conjunctions, oppositions, trines, squares, and sextiles.

What you'll need

Three pieces of information make a chart as accurate as possible:

1. Your birth date (month, day, and year).
2. Your birth time, as close to exact as you can find it. Birth certificates and hospital records usually have it to the minute.
3. Your birthplace. Search by city name above and pick the right match from the list, or enter latitude and longitude directly if you already know them.

Don't know your exact birth time? You can still get a chart

Check "I don't know my exact birth time" and the calculator will use noon as a stand-in. Here's what that changes and what it doesn't:

• The Sun's sign is almost always still correct: the Sun moves roughly one degree per day, so unless your birthday falls right on a sign boundary (within a day or so of the 19th to 23rd of a month), the Sun sign won't change based on time of day.
• The Moon's sign is usually still correct too, though it moves faster (about 13 degrees a day) and occasionally changes sign partway through a day.
• The Ascendant, Midheaven, and house placements are NOT reliable without a real birth time. The Ascendant alone shifts through an entire zodiac sign roughly every two hours, so a guessed time can put it in the wrong sign entirely.
• If you want an accurate Ascendant and house chart later, options include a birth certificate, hospital birth record, or (in the US) a state vital records office.

Worked example: reading a sample chart

Here's how the pieces fit together, using a sample chart for someone born July 4, 1990, at 8:30 AM in New York City. The reading guide walks through a full example like this in more depth, including how to weigh aspects between placements.

• Sun in Cancer: the core identity, here shaped by Cancer's themes of home, emotional depth, and protectiveness.
• Ascendant in Leo: the "first impression" sign, how this person tends to come across to others and approach new situations, here warm and confident on the surface.
• Moon in Sagittarius: the inner emotional world, here restless and drawn to freedom, contrasting with the more home-focused Sun.
• Mercury in the 11th house: communication style expressed through friendships, groups, and long-term goals rather than one-on-one settings.

A birth chart vs. a daily horoscope: not the same thing

A newspaper or app horoscope usually only uses your Sun sign, one of ten placements in a full chart, applied to everyone born in roughly the same four-week window regardless of year, time, or place of birth. A birth chart is different by design: it factors in the exact date, time, and place, which is why two people born on the same day can have noticeably different charts if their birth times or locations differ. Neither approach is "more correct" than the other; they're simply answering different questions. A Sun-sign horoscope answers "what's true for roughly one twelfth of all people born this year," while a birth chart answers "what does the sky specifically look like for this one person, at this one moment."

A second worked example, for contrast

To see how much a birth time and location can shift a chart, compare the July 4, 1990 New York example above to someone born on the exact same date and minute, but in Los Angeles instead:

• Sun and Moon signs stay identical: both depend only on the date and roughly the time of day, not the location, so a same-day, same-time birth keeps the same Sun in Cancer and (very likely) the same Moon sign regardless of where on Earth it happens.
• Ascendant and houses shift: Los Angeles sits roughly three time zones west of New York, so the same clock time corresponds to a different position of the sky relative to the horizon there. The Ascendant, Midheaven, and all twelve house cusps end up different, sometimes by an entire sign, even though the birth date and clock time are identical.
• This is exactly why the calculator asks for a place, not just a date and time. Skipping the location field, or entering the wrong city, is one of the most common reasons a calculated chart doesn't match what someone expects.

Getting the most accurate result

A few small details make a real difference to accuracy:

• Use the city you were actually born in, not the city you grew up in or currently live in. A hospital in a suburb can sometimes be technically in a neighboring town.
• If your birth certificate lists a time zone or UTC offset directly, that's more reliable than assuming a modern time zone applied decades ago; this calculator handles the historical lookup automatically once you enter the correct place and date, so you don't need to work out the offset yourself.
• Double check AM versus PM. A flipped 12-hour time is one of the most common data-entry mistakes and can shift the Ascendant and every house cusp significantly.
• If you're not sure your birth time is exact to the minute, treat the Ascendant and house cusps as approximate rather than precise; the Sun and Moon signs are far less sensitive to small timing errors.

The 12 houses at a glance

Each house represents a broad area of life. Where a house's cusp falls, and which planets sit inside it, colors how that area tends to play out for you. This calculator shows all twelve; here's what each one traditionally covers before you dig into your own results. The full houses guide goes deeper on each one, including angular versus succedent versus cadent houses.

How this calculator works

The math behind a birth chart is genuine astronomical calculation: planetary positions are computed for the exact date, time, and location you enter, converted to the tropical zodiac (the standard used in Western astrology), and mapped onto house cusps using the Placidus house system by default. Historical time zones and daylight saving rules are applied automatically based on where and when you were born, using the same underlying timezone database that browsers and operating systems rely on, so a birth in 1965 or 1990 is handled correctly, not just recent birth dates. Once your chart is calculated, the birth chart reading guide explains what your specific planet-in-sign and planet-in-house combinations actually mean, and how to weigh aspects when two placements seem to pull in different directions.

No birth data you enter here is ever sent to a server; see the privacy page for exactly how the calculation stays on your device.