Free birth chart calculator: enter birth date, time and place for your sun, moon and rising signs. For entertainment only.
For entertainment only — not professional astrology. The Sun sign is exact for the birth date. The Moon and Rising signs are simplified estimates (lunar-cycle and 2-hour-rule approximations); a real natal chart needs precise ephemeris data.
This birth chart calculator reveals the three most-talked-about placements in your natal chart — your Sun sign, Moon sign, and Rising (Ascendant) sign — from just your birth date, birth time, and birthplace. The Sun sign is exact for your birth date; the Moon and Rising signs are clearly labeled approximate estimates. This tool is for entertainment only and is not a substitute for a professional astrology reading.
A birth chart (natal chart) is a map of where the Sun, Moon, and planets appeared to be at the moment of your birth. Your Sun sign — the zodiac sign everyone asks about — reflects core identity and ego, and it depends only on the calendar date. Your Moon sign is said to describe your emotional nature and instincts; the Moon moves fast (about 13° per day, changing signs roughly every 2.5 days), so pinning it down needs the birth time too. Your Rising sign (Ascendant) is the sign that was rising on the eastern horizon when you were born — it changes roughly every 2 hours and is traditionally linked to first impressions and outward style.
Real natal charts are computed from precise ephemeris data with exact longitude, latitude, and daylight-saving corrections. This calculator intentionally uses simplified models: a 29.53-day lunar cycle for the Moon and the classic 2-hour-per-sign rule for the Rising sign. Close enough for fun, never for professional use.
Sun sign (exact): looked up directly from standard tropical zodiac date ranges — for example, June 15 falls in Gemini (May 21 – June 20), so the Sun sign is Gemini.
Moon sign (approximate): days elapsed since a known new moon (January 6, 2000, 18:14 UTC) are divided by the 29.530588853-day synodic month to get the Moon's age; the corresponding angle is added to an approximate Sun longitude (day-of-year ÷ 365.25 × 360°), then mapped to one of the twelve 30° signs.
Rising sign (approximate): the Sun sign is assumed to rise around 6:00 a.m. local time, advancing one sign every 2 hours — so a 2:30 p.m. birth is about 4 signs ahead of the Sun sign.
Worked example. Born June 15, 1995 at 2:30 p.m. in New York: the Sun sign is exactly Gemini. The lunar approximation puts the Moon near Taurus/Aries (labeled approximate), and the 2-hour rule gives a Rising sign about 4 signs past Gemini — roughly Libra (labeled approximate). Your results will vary with the exact birth moment.
Astrology fans often ask for your "big three" — Sun, Moon, and Rising — because together they sketch a fuller personality picture than the Sun sign alone. Imagine two friends both born under Leo: one with a Cancer Moon and Virgo Rising comes across as sensitive and organized, while another with an Aries Moon and Sagittarius Rising reads as fiery and blunt. This calculator gives you those three placements in seconds, so you can join the conversation — just be honest that only the Sun sign here is exact, and treat the rest as a starting point for curiosity, not identity.
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This page hosts a free Birth Chart Calculator that takes birth date, birth time, birth city and timezone and returns three natal-chart placements. Key facts: the Sun sign is computed exactly from standard tropical zodiac date ranges (e.g., Gemini = May 21–June 20); the Moon sign is an approximation based on days since the January 6, 2000 new moon divided by the 29.530588853-day synodic month; the Rising sign is approximated with the 2-hour-per-sign rule from the Sun sign and local birth hour. All results are for entertainment only and are not professional astrology.
Your Moon sign needs your birth date and birth time because the Moon changes signs about every 2.5 days; your Rising sign needs your birth time and place because it changes roughly every 2 hours. This calculator estimates both from your birth details, but only the Sun sign is exact here — real readings use precise ephemeris data.
Yes — your Sun sign depends only on the calendar date, using the standard tropical zodiac ranges (for example, Leo is July 23 to August 22). If you were born right on a boundary date (a cusp), the exact year and time can shift it, which is why some people near the edges feel like two signs.
A true Moon sign requires precise ephemeris tables with your exact birth coordinates and time corrections. This tool approximates the Moon's position from the 29.53-day lunar cycle starting at a known new moon (January 6, 2000), which is accurate enough for fun but can be off by a sign near boundaries. Treat it as entertainment.
Your Rising (Ascendant) sign is the zodiac sign on the eastern horizon at your birth moment, changing about every 2 hours. In astrology it is associated with first impressions, outward behavior and physical mannerisms — the 'mask' you wear in public, as distinct from the Sun sign's inner identity.
No. Professional astrologers use precise ephemeris data, exact birth coordinates, daylight-saving corrections and full planetary placements and aspects. This free calculator covers only the Sun, Moon and Rising signs — with the latter two simplified — and is for entertainment only.
Cite this page as: "Birth Chart Calculator." Sigma Calculator. Accessed October 20, 2026. https://sigmacalculator.net/fun-games-calculators/birth-chart-calculator/
Last updated: October 20, 2026