How accurate is this free birth chart calculator?

Our calculator uses the Astronomy Engine library based on VSOP87 planetary theory, the same models used by professional astronomers. Accuracy depends primarily on having your exact birth time — even a 15-minute difference can change your Rising sign.

What are Sun, Moon, and Rising signs?

Your Sun sign represents your core identity and ego. Your Moon sign reveals your emotional nature and inner world. Your Rising sign (Ascendant) is the zodiac sign that was on the eastern horizon at the moment of your birth — it shapes how others perceive you and your outward personality.

Free Birth Chart Generator

Calculate your Sun, Moon & Rising signs instantly. Download a beautiful card to share on Instagram.

Your Name

Date of Birth

Time of Birth

I don't know my birth time

Place of Birth

UTC Offset (Timezone)

Auto-selected based on location. Adjust if needed for historical timezone or daylight saving.

Mapping the stars at your moment of birth...

Sun Sign

Moon Sign

Rising Sign

Planetary Positions

Planet	Sign	Degree

Your Shareable Card

Want a Deeper Reading?

Get a full AI-powered birth chart interpretation with personality insights, love compatibility, and cosmic timing — free on WhatsApp.

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Frequently Asked Questions

How accurate is this birth chart calculator?

Our calculator uses the Astronomy Engine library, which is based on the VSOP87 planetary theory — the same models used by professional astronomers. Planetary positions are accurate to within 1 arcminute. The most important factor for accuracy is having your exact birth time — even a 15-minute difference can shift your Rising sign.

What if I don't know my exact birth time?

Check the "I don't know my birth time" box and we'll use noon as a default. Your Sun sign and most planetary positions will still be accurate. However, the Rising sign (Ascendant) and Moon sign may be off — the Moon moves about 12-13 degrees per day, and the Ascendant changes sign roughly every 2 hours. Check your birth certificate or hospital records for the most precise time.

Can I share my birth chart on Instagram?

Absolutely! After generating your chart, click "Download for Instagram" to save a beautifully designed card optimized for Instagram stories (1080 x 1920 pixels). On mobile, you can also tap "Share" to send it directly to any app. Tag us @askmercurious to get featured!