What is a birth chart?

A map of where the Sun, Moon and planets sat, seen from Earth, at the moment you were born. The positions are astronomy; the meanings laid over them are astrological tradition. Together they form the chart astrologers read.

Do I need my exact birth time?

For the planets, no — they move slowly enough that a day's uncertainty rarely changes a sign. For your rising sign, yes. The Ascendant moves through a full sign roughly every two hours, so without a time it cannot be calculated honestly. The Moon can also change sign within a single day.

What are the big three?

Sun, Moon and Rising. The Sun is your core identity, the Moon your emotional nature, and the Rising sign the face you lead with. Most people who know one placement know their Sun; the other two usually explain more.

What does retrograde mean in a birth chart?

It means the planet appeared to move backwards from Earth at your birth. Tradition reads that as the planet's function turning inward — slower to show outwardly, often stronger internally. About one person in five has three or more, so it is common rather than remarkable.

No. The whole calculation runs in your browser using published astronomical algorithms. Your birth details are never sent to a server, and no account or email is required.

How accurate is this calculator?

Planetary positions are computed from JPL's orbital elements and are accurate to a few arcminutes — far finer than the 30-degree width of a zodiac sign. The Ascendant is derived from local sidereal time using the IANA timezone database, so historical daylight-saving rules are handled correctly.

Free · no signup · runs in your browser

Birth Chart Calculator

Enter your birth date to get your full natal chart — Sun, Moon, rising sign and every planet, with what each placement means. Positions are computed from real orbital mechanics, not looked up in a table. Add a birth time and city and you also get your Ascendant and Midheaven.

Date of birth *

Time of birth (optional)

Place of birth (optional — needed for your rising sign)

Runs entirely in your browser. Nothing is sent anywhere, and no email is required.

What each placement describes

Body	Governs	The question it answers
Sun	your core identity and what you are here to become	Who am I when I am most myself?
Moon	your emotional nature and what makes you feel safe	What do I need in order to feel settled?
Mercury	how you think, speak and process information	How does my mind actually work?
Venus	what you value, how you love and what you find beautiful	What draws me, and how do I show affection?
Mars	your drive, appetite and how you handle conflict	How do I pursue what I want?
Jupiter	where you expand, what you believe and where luck tends to find you	Where do I grow most easily?
Saturn	your limits, discipline and the lesson you keep being handed	What do I have to earn the hard way?
Uranus	where you break from convention and what makes you unusual	Where am I not like the people I grew up with?
Neptune	your imagination, longing and where the edges blur	Where do I dissolve, dream, or deceive myself?
Pluto	your relationship with power and what transforms you	What in me keeps dying and reforming?

How to read your chart

Start with the big three. Your Sunis the identity you are growing into — the thing people mean by “your sign.” Your Moon is the private layer: what you need to feel safe, and how you react before you have decided how to react. Your rising sign is the doorway — the manner you meet a room with, which is often the part others describe first and you recognise least.

After that, read by speed. Mercury, Venus and Mars change sign every few weeks and describe personal texture — how you think, what draws you, how you push. Jupiter and Saturn take one to three years each and describe the shape of a chapter. Uranus, Neptune and Pluto take years to decades, so they say more about your generation than about you; where they sit matters mostly for how they aspect the rest.

Why the birth time matters

The Ascendant is the degree of the zodiac climbing over the eastern horizon at your birth. Earth turns once a day, so that degree moves through all twelve signs in twenty-four hours — about one sign every two hours. A chart that gives you a rising sign without a birth time has guessed.

The Moon is the other time-sensitive placement: it covers roughly 13° a day, so on about one day in three it changes sign between midnight and midnight. This calculator tells you when that happened on your date rather than silently picking one.

Where this sits in the Atlas

Your chart is a snapshot of one moment. The sky kept moving, and the lunar calendar and retrograde tracker follow where it is now. If the birth chart is how you locate yourself in time, the resonance journey and the cosmic lineages are how the Atlas locates you in origin. The starseed markings page reads the same chart for a different signal.

Common questions

What is a birth chart?: A map of where the Sun, Moon and planets sat, seen from Earth, at the moment you were born. The positions are astronomy; the meanings laid over them are astrological tradition. Together they form the chart astrologers read.
Do I need my exact birth time?: For the planets, no — they move slowly enough that a day's uncertainty rarely changes a sign. For your rising sign, yes. The Ascendant moves through a full sign roughly every two hours, so without a time it cannot be calculated honestly. The Moon can also change sign within a single day.
What are the big three?: Sun, Moon and Rising. The Sun is your core identity, the Moon your emotional nature, and the Rising sign the face you lead with. Most people who know one placement know their Sun; the other two usually explain more.
What does retrograde mean in a birth chart?: It means the planet appeared to move backwards from Earth at your birth. Tradition reads that as the planet's function turning inward — slower to show outwardly, often stronger internally. About one person in five has three or more, so it is common rather than remarkable.
Is my data stored?: No. The whole calculation runs in your browser using published astronomical algorithms. Your birth details are never sent to a server, and no account or email is required.
How accurate is this calculator?: Planetary positions are computed from JPL's orbital elements and are accurate to a few arcminutes — far finer than the 30-degree width of a zodiac sign. The Ascendant is derived from local sidereal time using the IANA timezone database, so historical daylight-saving rules are handled correctly.