⌂ Free Astrology House Calculator: All Twelve Cusps

Umbriel's free house calculator gives all twelve of your house cusps and places every planet in a house, from your birth date, time and place.

The houses divide the chart into twelve areas of life: self, money, communication, home, and so on round to the twelfth. Where the signs describe a style, the houses describe a place: the part of a life a planet's business shows up in. It is usually the layer that makes a chart feel specific, not generic.

And it is the layer with the least agreement. The signs are fixed thirty-degree divisions; the houses are not. A dozen systems are in serious use and they cut the sky up differently. Placidus by time, Whole Sign by whole signs, Regiomontanus and Koch by different great circles. The same chart can put Venus in the 9th under one and the 10th under another. Neither is a bug. There is no experiment that settles it.

Two practical notes. Every system puts the Ascendant on the 1st cusp, so your rising sign never changes between them, but in Whole Sign the Midheaven is not the 10th cusp and can land in the 9th or 11th, which surprises people moving over from Placidus. And Placidus, which is the most widely used, breaks down near the poles: above roughly 66° latitude it cannot produce houses at all, so a birth in far northern Scandinavia or Alaska needs a different system entirely.

This tool computes the twelve house cusps of your chart and the house each body falls in, from your birth date, time and place. Umbriel first turns your birth moment into local sidereal time using your longitude, then finds the Ascendant and Midheaven from that time, the obliquity of the ecliptic and your latitude. The remaining cusps come from whichever system is selected; the default is Placidus, and Whole Sign, Equal, Koch, Regiomontanus, Campanus, Porphyry, Topocentric, Alcabitius, Morinus, Meridian, Vehlow and others are available. Whole Sign starts house 1 at 0 degrees of the Ascendant's sign, so its cusps are the sign boundaries, while Equal houses start at the Ascendant's exact degree and step 30 degrees each. A planet's house is found by testing which pair of consecutive cusps its longitude lies between. The systems genuinely disagree, sometimes by a whole house, because they are different definitions and not different measurements. Every one of them needs an exact birth time: with no time Umbriel returns no cusps and no houses rather than filling in noon, and offers solar houses (whole signs counted from the Sun's sign) only under that label. If a system cannot be drawn at your latitude, for example when the Placidus quadrants collapse, Umbriel falls back to Equal houses and records that the fallback happened. Against an independent implementation the Ascendant and Midheaven agree to under 0.5 arcminutes, and the Midheaven advances roughly a degree every four minutes of clock time, so the birth time you enter is the main source of uncertainty.