Equal House System Chart Calculator
Equal House splits your chart into twelve equal 30-degree houses measured from your exact Ascendant, so no house is ever compressed or stretched. It works reliably anywhere on Earth, including high-latitude birthplaces where systems like Placidus or Koch can distort or fail.How it works ↓
Calculating your placements…
The Equal House system divides the chart into twelve equal 30-degree houses starting from your Ascendant, avoiding the compressed or stretched houses that quadrant systems can produce near the poles.
Twelve equal 30-degree houses, measured from your Ascendant's exact degree
Equal House starts your 1st house cusp exactly at your Ascendant's degree, then places every following house cusp exactly 30 degrees further around the zodiac. Unlike Whole Sign, which starts each house at the beginning of a sign, Equal House keeps your precise Ascendant degree as the anchor point, so a house cusp can fall in the middle of a sign rather than at its start.
This produces houses that are always geometrically identical in size, a distinction from quadrant systems like Placidus, Koch, Campanus, and Regiomontanus, where house sizes vary depending on birthplace latitude and time of birth.
Equal House has no latitude failure mode
Quadrant systems calculate houses using time arcs or great-circle projections tied to your birthplace latitude, and at high latitudes, inside or near the polar circle, that math can produce houses of wildly unequal size or fail to compute at all. Equal House sidesteps this completely, since it never references latitude-dependent time arcs or projections; it's simple arithmetic on a fixed 30-degree interval.
This is why Equal House is the commonly recommended fallback for high-latitude births where Placidus, Koch, Campanus, or Regiomontanus produce distorted or undefined results.
Reach for Equal House for high-latitude births or when you want houses of guaranteed equal size
Equal House is the practical choice any time a birthplace sits far enough north or south that quadrant systems become unreliable, and it's also a reasonable default if you simply prefer houses of uniform size over the varying sizes quadrant systems produce.
How Equal House compares to Whole Sign and the quadrant systems
Equal House and Whole Sign are the two non-quadrant systems in this group, and they're the two most likely to be confused, both give even divisions with no latitude risk. The difference is the anchor: Whole Sign anchors to the start of your Ascendant's sign, while Equal House anchors to your Ascendant's exact degree, so their cusps only coincide when your Ascendant happens to fall at 0 degrees of a sign.
Against Placidus, Koch, Campanus, and Regiomontanus, Equal House cusps will diverge more the further your birthplace is from the equator, since those systems' house sizes shrink or expand with latitude while Equal House's don't move at all.
Frequently Asked Questions
Will Equal House give me a different Ascendant or Midheaven?
No, your Ascendant and Midheaven are calculated the same way regardless of house system, Equal House only changes the cusps of the houses in between, not the angles themselves.
Is Equal House "less accurate" because it's simpler?
Simplicity isn't the same as inaccuracy, Equal House is a genuine, long-used house-division method, not an approximation of a quadrant system. Different house systems reflect different definitions of a house, not competing measurements of one true answer.