Equal House System

The Equal House system is a simple division: take the exact degree of the ascendant, and then create twelve houses each exactly 30 degrees wide, starting from there. If your ascendant is at 14 degrees Aries, your first house runs from 14 Aries to 14 Taurus, your second house from 14 Taurus to 14 Gemini, and so on around the wheel.

Equal House sits between Whole Sign and Placidus in its approach. Unlike Whole Sign, it preserves the exact degree of the ascendant as the start of the first house. Unlike Placidus, it ignores the actual time-based geometry of the diurnal arc and gives all houses identical sizes. The result is a system that is mathematically clean and stable at all latitudes but does not preserve the relationship between the midheaven and the tenth house cusp.

In Equal House, the midheaven exists as a separate point but is not the cusp of the tenth house. The tenth house cusp is the point exactly 270 degrees after the ascendant. This means the MC can fall in the ninth, tenth, or eleventh house depending on the chart, which some astrologers find awkward and others find reasonable.

Equal House remains in active use, especially in British astrological tradition where it has historical roots. It is rarely a default in modern software but is offered as an option in most professional astrology programs.