Signs tell how, houses tell where
The zodiac signs describe the style of a planet, and the houses describe the part of life where astrologers expect that planet to show up. Your Venus may be in Taurus by sign and in the tenth house by position, which would be read as a love of beauty expressed through work or public life.
Houses are fixed to the horizon and meridian of your birthplace at your birth moment. That is why two people born on the same day in the same city can have very different house placements if their birth times are a few hours apart.
The three house systems we offer
Placidus is our default and the most widely used system in the United States. It divides the sky by time: each house covers the arc a point travels in a set fraction of its daily path above or below the horizon. The result is twelve houses of unequal size, with some spanning more than 40 degrees and others fewer than 20.
Whole Sign houses are the oldest approach. The entire rising sign becomes the first house, the next sign the second, and so on, so every house is exactly one sign. Equal houses start at the exact Ascendant degree and mark off twelve slices of 30 degrees each.
None of these is the single correct answer, so the tool lets you compare all three.
Why Placidus breaks down near the poles
Placidus depends on how long each degree of the zodiac takes to rise. Above roughly 66 degrees of latitude, near the Arctic and Antarctic circles, some degrees never rise or never set on certain days, and the formula has no solution.
When a birthplace is that far north or south, we switch to Whole Sign houses automatically and show a note. Births in places such as northern Alaska, Norway or Finland are the usual cases.
The twelve houses in one line each
First house: self, body, first impressions and the way you meet the world.
Second house: money you earn, possessions and what you value.
Third house: siblings, neighbors, daily talk, short trips and early learning.
Fourth house: home, family roots, private life and the end of matters.
Fifth house: romance, play, creative work, hobbies and pleasure.
Sixth house: daily routines, chores, jobs, pets and habits of care.
Seventh house: partners, marriage, open rivals and one-on-one contracts.
Eighth house: shared money, debts, inheritance, intimacy and deep change.
Ninth house: higher study, long travel, belief, law and publishing.
Tenth house: career, reputation, status and public role.
Eleventh house: friends, groups, networks, hopes and wishes.
Twelfth house: solitude, hidden matters, retreat, rest and things kept behind the scenes.
Getting the birth time right
The house cusps shift about one degree every four minutes, so a time rounded to the nearest hour can move a planet into the next house. A birth certificate time is the best source. We convert it to UTC with the time zone rules that applied at your birthplace on that date, including daylight saving time.
Without a birth time, houses cannot be calculated. In that case, use the birth chart for signs only, and check the rising sign calculator and midheaven calculator once you find your time.