In a standard natal chart, there are 12 houses, each ruling different aspects of our lives and personalities. It often comes as frustrating to many astrology students once they start moving through their astrology learning to find that there are actually many different ways of calculating the houses. Of course, astrology just can’t be simple! Probably the most common question I get asked by intermediate students is, “Which house systems should I use?”
My answer is always the same - Use the house system you feel most comfortable with. Many people think there is only one right house system to use, but that’s hogwash. Anyone who tries to tell you that is probably a know-it-all, ultra controlling, or needs to get their head out of their you-know-what!
There is no right or wrong answer for which house system to use in astrology. I encourage experimentation with the different house systems to see which you connect with most. But in truth, I find most of us end up using the house system we first started with. Maybe that’s pure laziness, maybe it’s just the most familiar since it’s the one we began with, or maybe it’s the one we were meant to use and so it’s the one that found us first. Who knows?
The most commonly used house system in Western astrology is Placidus, but I find that the most commonly used house system among astrologers tends to be Koch. It seems to be a “fancier” version of Placidus. But you’ll also find a lot of astrologers who use Equal or Whole Sign houses, especially if they’re more old-school astrologers (because they’re the easiest to compute by hand; many of the house systems are time-consuming to do by hand, so Whole Sign and Equal houses were the most commonly used before computers and programs and sites like astro.com came along).
Personally, I use Placidus as my first choice. It’s what I started with and what I feel most comfortable with. If the houses in a Placidus chart get too wonky, then I’ll try Koch. “Wonky” houses for me is when there are houses that are 2 signs or larger or under 20 degrees. This tends to occur with people born near the poles, so astrologers based in those areas tend to only use Equal, which is my last-resort if the Koch houses are also wonky.
If you want to go through the different house systems, Wikipedia actually has a good list:
And on astro.com, you can play around with the house systems in Extended Chart Selection; here they describe the different house systems you can use on astro.com: