Your birth chart, calculated precisely
Free astrology calculators built on real astronomy: planet positions checked against NASA JPL Horizons, historical time zones handled for you, and nothing stored.
Calculators
- Birth chart calculatorFull natal chart: planets, Ascendant, houses and aspects, drawn as a chart wheel.
- Rising sign (Big Three)Sun, Moon and rising signs, plus how much your birth time can be off.
- Moon sign calculatorYour Moon sign with or without a birth time.
- Venus sign calculatorYour Venus sign: love, attraction and values.
- Synastry chartCompare two charts: Sun–Moon, Venus–Mars and every aspect between you.
- Zodiac compatibilityAll 78 sign pairings: how every two signs get along in love, and why.
- What zodiac sign am I?Your Sun sign by birthday, with exact answers for cusp dates.
- Is Mercury retrograde?Live status, countdown and every date this year and next.
Why Natal Chart Lab
- Accurate positions. Within about 20 arcseconds of NASA JPL Horizons in our published comparison.
- Birth-time aware. We tell you when the Moon changed signs on your birthday, and how many minutes your birth time can be off before your rising sign changes.
- Private. Charts are calculated on request and never saved. Share cards show only your signs.
- Open data. Retrograde dates for 1950–2050 are free to download and cite.
Astrology is a symbolic and cultural tradition. The planetary positions on this site are calculated with astronomical accuracy; the interpretations describe what astrologers associate with them and are not scientifically validated predictions about personality, relationships or the future.