How do I calculate my astrology houses?
Enter your birth date, exact time, and city above — the calculator casts your chart and lays out all 12 house cusp signs, their rulers, and every planet by house in one view.
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Astrology Houses Calculator — All 12 Houses & Rulers
Free astrology houses calculator: see all 12 house cusp signs, house rulers, and which planets sit in each house of your birth chart.
What the 12 houses map
If the signs describe how planetary energy expresses, the houses describe where it lands. The twelve houses divide the chart into life areas — the 1st is self and appearance, the 2nd money and values, the 7th partnership, the 10th career and reputation, the 12th the unconscious and what works behind the scenes. Planets sitting in a house show where your chart's energy naturally concentrates.
Why houses need an exact birth time
The whole chart wheel turns once every 24 hours — the Ascendant alone advances on the order of a degree every few minutes — so even a small error in birth time can shift a planet from one house into the next and change the reading. Different house systems, such as Placidus and Whole Sign, can also place the same planet in different houses because they divide the wheel by different rules. An accurate birth time is what makes the twelve-house layout trustworthy.
Reading cusps, rulers, and planets by house
Each house has a sign on its cusp; the planet that rules that sign is the house ruler, and where that ruler sits links the two life areas together. A 2nd-house cusp in Aries points to Mars, so wherever Mars lives describes how you earn and value. Empty houses are completely normal — they simply run on their ruler rather than a resident planet. This calculator lays out all twelve at once.
The 12 houses at a glance
The 1st house is self, body, and first impressions; the 2nd money, possessions, and self-worth; the 3rd communication, siblings, and the local world; the 4th home, family, and roots. The 5th rules creativity, romance, and children; the 6th work, routines, and health; the 7th marriage and one-to-one partnership; the 8th shared resources, intimacy, and transformation. The 9th covers beliefs, study, and travel; the 10th career and public reputation; the 11th friends, community, and the future; and the 12th the unconscious, solitude, and what works behind the scenes. Run the calculator above to see which signs and planets fill each of yours.
Placidus, Whole Sign, and why calculators disagree
House systems are different rules for slicing the same sky. This calculator uses Placidus — the most widely used modern system, which divides the houses by rising time and therefore needs your exact birth time and place (at extreme polar latitudes, where Placidus is undefined, it falls back to Porphyry). Whole Sign astrology instead assigns each house to one complete sign, so cusp degrees disappear entirely. The planets never move between systems — only the house boundaries do — which is why two sites can put the same Moon in different houses. If a result surprises you, the first thing to check is which house system the other tool used.
Questions
What is a house in astrology?
Houses divide the chart into life areas such as relationships, career, home, and health.
Why do houses need exact birth time?
House cusps shift quickly with time and location, so precise birth details improve accuracy.
What is a house ruler?
A house ruler is the planet that rules the sign on that house cusp and helps describe how that life area operates.
What house is my Moon in?
Enter your birth date, time, and city above — the calculator shows which house every planet occupies, including your Moon. The Moon's house is where your emotional life concentrates: the 4th points it at home and family, the 7th at close partnership, the 10th at career and public life.