Determine House Size

House size in astrology refers to the number of degrees each house spans in the birth chart. Traditionally, each house is considered to occupy 30 degrees of the zodiac, but in reality, due to the curvature of the Earth and varying latitudes, houses can differ in size. Here's how you can determine the size of each house in the birth chart:

1.      Ascertain Birth Details: Gather the exact time (including hours and minutes), date, and place of birth of the individual.

2.      Determine Local Mean Time (LMT): Adjust the birth time from Greenwich Mean Time (GMT) or Coordinated Universal Time (UTC) to Local Mean Time (LMT) for the place of birth. Each location has its own time zone offset from GMT/UTC.

3.      Calculate Sidereal Time (ST): Use the LMT to calculate the Sidereal Time (ST) at the birthplace. Sidereal Time represents the position of the vernal equinox and is necessary for house size calculation.

4.      Calculate Ascendant Degree: Calculate the Ascendant (Lagna) degree using astrological software or tables, incorporating the Sidereal Time and the individual's birth location.

5.      Calculate House Cusps: Proceed counterclockwise from the Ascendant, calculating the cusps of each house. The difference in degrees between the cusps of adjacent houses determines the size of each house.

6.      Determine House Size: Measure the degrees between each cusp to determine the size of each house. Subtract the degree of the previous cusp from the degree of the current cusp. The result represents the size of the house in degrees.

7.      Adjust for Latitude: In some cases, particularly at extreme latitudes, houses may vary significantly in size. Astrologers may use different house division systems or adjust house sizes based on the individual's location to account for these variations.

8.      Midheaven (MC): The Midheaven marks the beginning of the tenth house. Calculate its position using the Sidereal Time and other relevant factors, similar to how you calculated the Ascendant.

By determining the size of each house, you gain insights into the emphasis placed on different areas of life in the individual's birth chart. Houses with larger sizes may indicate areas of greater significance or prominence in the individual's life, while smaller houses may represent areas of lesser emphasis.