Porphyry Vs Placidus Vs Whole Sign

When it comes to astrology, one of the most important factors is determining the placement of the planets in the different houses of a birth chart. There are several different house systems that astrologers can use to accomplish this, and three of the most popular are Porphyry, Placidus, and Whole Sign.

While each of these house systems has its own unique strengths and weaknesses, choosing the right one for a particular reading can make a big difference in the accuracy and relevance of the information obtained from the chart.

In this article, we’ll take a closer look at each of these house systems, discussing their origins, how they work, and some of the pros and cons of each. We’ll also explore some of the factors to consider when choosing which system to use for a particular reading, and some practical tips for working with each system effectively.

Porphyry House System

The Porphyry house system is named after the Greek philosopher and mathematician Porphyry of Tyre, who is credited with developing this system of house division sometime in the 3rd century AD. Porphyry is a simple, straightforward system that divides the ecliptic (the apparent path of the Sun across the sky) into twelve equal sections based on the degree of the Ascendant and Midheaven.

One of the strengths of Porphyry is that it is easy to learn and understand, making it a popular choice for beginners in astrology. It also tends to produce clear and concise information, making it a useful tool for specific questions or areas of focus in a reading.

However, one of the weaknesses of Porphyry is that it does not account for the curvature of the Earth, which means that some planets may be left out of certain houses depending on their distance from the ecliptic. This can result in some inaccuracies or inconsistencies in the chart that can be difficult to interpret.

Placidus House System

The Placidus house system is the most widely used house system in modern Western astrology, named after the French astronomer and astrologer Placidus de Titis (1603-1668). Placidus is a complex system that takes into account the curvature of the Earth and the varying lengths of each degree of longitude across the globe.

To calculate a Placidus chart, the ecliptic is first divided into twelve equal segments based on the degree of the Ascendant. The cusps of each house are then determined by dividing the arc between the Ascendant and Midheaven into three parts, and projecting those points onto the ecliptic. This creates a system where the houses are asymmetrical and can vary in size based on the latitude of the birthplace.

One of the strengths of Placidus is that it accounts for the curvature of the Earth and can produce highly accurate and detailed charts, especially when used in conjunction with more advanced astrological techniques such as transits and progressions. It can also provide important insights into subtle or nuanced areas of a person’s life and can illuminate connections between seemingly disparate areas of the chart.

However, one of the weaknesses of Placidus is its complexity, which can make it more difficult to understand and use effectively. It can also produce charts that are highly specific and focused on particular areas of the person’s life, which may be less useful or relevant in some contexts.

Whole Sign House System

The Whole Sign house system is one of the oldest and simplest forms of house division, dating back to ancient Hellenistic astrology. In this system, the entire sign of the Ascendant (rising sign) is considered to be the first house, with each subsequent sign representing the succeeding house, and so on.

One of the strengths of Whole Sign is its simplicity and effectiveness, which make it a useful tool for readings focusing on general trends or broad areas of a person’s life. It also provides a holistic view of the chart, emphasizing the interconnections and relationships between different areas of the person’s life and emphasizing the unity of the chart as a whole.

However, one of the weaknesses of Whole Sign is that it can produce less specific or precise information about particular areas of a person’s life, which may be less useful or relevant in some contexts. It can also lead to charts that are overly generalized or lacking in detail, which can limit the accuracy and effectiveness of the reading.

Choosing the Right House System

When it comes to choosing the right house system for a particular reading, there are several factors to consider. Some of the key factors include the purpose of the reading (e.g. general trends, specific questions, overall life review), the experience level of the astrologer and client, and the context and cultural background of the reading.

In general, beginners in astrology may find Porphyry or Whole Sign more accessible and easier to use effectively, while more advanced astrologers may benefit from the precision and detail of Placidus. Reading for someone from a different culture or with a different worldview may also require adjustment or adaptation of the house system to better reflect their worldview and life experiences.

Ultimately, the choice of house system is a personal and contextual one, and there is no one “right” answer. Every system has its strengths and weaknesses, and every chart is unique and complex. However, by understanding the basics of each system and considering the needs and context of the reading, an astrologer can choose the most appropriate system for each case and provide a more accurate and effective reading as a result.


Porphyry, Placidus, and Whole Sign are three of the most popular and widely used house systems in modern astrology, each with their own unique strengths and weaknesses. Choosing the right system for a particular reading can make a big difference in the accuracy and relevance of the information obtained from the chart, and requires careful consideration of factors such as the purpose of the reading, experience level of the astrologer and client, and cultural context.

As with all areas of astrology, there is always more to learn and explore, and no one system or approach can encompass the full complexity and diversity of human experience. However, by using these house systems wisely and effectively, astrologers can gain deeper insights into the lives and destinies of their clients, and help them navigate the challenges and opportunities of this mysterious and wondrous universe we call home.