What do you mean, “Which House System” do I prefer? How should I know?

Look up into the sky and you can see the Sun, Moon, and most of the planets an astrologer uses in your birth chart. But do you see any little lines, separating the sky into 12 pie slices, or “houses” like the ones you see on a birth chart? Hopefully not. If you do, fine-tune your reception.

Astrologers use a variety of “house systems,” or methods of dividing up the sky into twelve sections. I use the Koch house system; another very popular house system for birth charts is Placidus. (IF YOU CALCULATE YOUR CHART AT ASTRO.COM and don’t change the default house system, it will be calculated using Placidus.)

The Ascendant (1st house cusp), IC (4th house cusp), Descendant (7th house cusp), and MC (10th house cusp) tend to be the same from one house system to the next; however, the other house cusps can vary. Therefore, planets can fall in different houses depending on what house system is used to calculate your chart.

Astrologers tend to be uncommonly attached to their favorite house systems. If you ever find yourself among a group of astrologers and the conversation lags, introduce the subject of house systems and watch the fur fly! Everyone has strong opinions about which is the best and why. Here is a good explanation of different house systems and their theoretical and mathematical underpinnings. For many astrologers, though, house systems tend to be a matter of habit.

If you’ve previously had charts or reports calculated and did not specify a house system, you may well have received something that had been calculated using a house system different from the one I use – most likely, Placidus. So if the chart or report that I send you looks different from what you’re used to, that’s the most likely reason (unless you provided a different time or place of birth to that other astrologer).

I will of course replace reports at no charge if there has been an error on my part. I will charge full fee, however, to replace a report I sent you with one that is calculated using a different house system. So when you order, please specify the house system you want me to use, or I will use my favorite – Koch.

Want to look at your chart in different house systems before you order? You can do that for free at Here’s a video to show you how!