Should Astrologers Know How to Calculate Natal Charts by Hand?

I remember vividly the first time I ever cried in school. It was the ’93-’94 school year and I was 6 or 7 years old. I could not wrap my head around multiplication. “If you have three sets of two apples, how many apples do you have?” my teacher kept asking. “Five” I kept responding, thinking it was an addition problem. She grew increasingly frustrated and I ended up losing my shit in front of the class screaming “Fiiive!” in a sort of inverse of the “2+2=5” torture scene from 1984, as the other children quietly looked on in bemused alarm. From then on, I grew up with a bit of a complex around math, and to a lesser extent, apples.

I wasn’t able to completely memorize multiplications up to 12 until the spring of 1997 at age 9. I knew I was one of the last in my class to properly understand it because we would play a completely unproblematic game where everyone would stand up, be randomly called upon to answer a multiplication problem, and only get to sit down if we got it right. I was often the last or one of the last students standing. One time my teacher even held the class past the bell until I got it right, which made me extremely popular with my classmates. My school reports year after year read the same: High marks in everything, but different teachers left comments about my “crisis of confidence” and “psychological terror” of math. It couldn’t have been the shame-based math games, of course not.

I say all this to say that if I was born in a time before computers, nothing about my early educational history would suggest I would be a strong candidate to be an astrologer, which until the late 20th century, required a pretty strong stomach for math. The only math class I ever excelled in was Geometry which I took in the ’03-’04 school year at age 15-16. This dovetailed serendipitously with my first dive into astrology. My teacher had a reputation for being somewhat idiosyncratic and he happened to lean in more heavily on the Pythagorean and spiritual dimension of numbers (this was in a Catholic high school). These classes happened in the same period that I was first reading about and understanding the nature of sextiles, squares, trines and oppositions, and somehow it clicked. Seemingly the approach that worked for me was “Math, but make it woo”.

I’m part of the first generation of astrologers that did not ever need to learn how to manually calculate a chart in order to practice astrology. It’s never been easier to cast a natal chart more precisely than ever before. From the perspective of astrologers in past centuries who toiled for every calculation, it’s not hard to imagine they would likely see astrological software as a truly miraculous development. It’s difficult to appreciate it now that it’s become old hat, but my appreciation has been recently renewed over the course of my preparation for the NCGR-PAA Level I Certification Exam, which among other things requires you to calculate a natal chart by hand, including Placidus divisions. Gulp.

I knew that I would eventually have to master some of the math behind astrology, but I wasn’t sure when that point would come. The first sign I received that I needed to up my game was when I was unexpectedly blindsided by the question of what sidereal times were used for in the ephemeris. Unfortunately, that embarrassing moment occurred while I was on a May 2021 episode of the Astrology Podcast with Chris Brennan about using the ephemeris.

Oh, god. I made some efforts in the following months to learn how to calculate charts, but at that time I was consumed with client work and life otherwise got too busy, so I put it off.

I’m not sure at what point this was in 2022, but in thinking ahead about the Saturn-Neptune conjunction, I began to be concerned that the Neptune in Pisces wave that had brought about the mainstreaming of astrology to popular culture might be headed for a Saturnian reckoning. Here are three things that are consistent with the Saturn-Neptune complex that I’m not exactly looking forward to:

  • Consequential embarrassments or failures in the field, the exposure of frauds and scammers.
  • A critical backlash to astrology, a renewed and re-energized skeptical movement, potential censorship of astrology online or regulation/legal prohibition of astrology as the most extreme possibility
  • Economic difficulties straining the livelihoods of astrologers, a potential culling of the field.

The positive potentials of the transit that also belong to the Saturn-Neptune complex include the following:

  • The traditional revival in astrology that began in the late 80’s/early 90’s (the previous Saturn-Neptune conjunction) reaches full maturity or a new inflection point.
  • A movement toward standardization or certification to “professionalize” the field.
  • The formation of new astrological institutions or the merging of old ones.

Given some of the fears I have for this transit, I’ve been preparing. This is why despite having already built up a reputation for myself, I decided to still achieve certification by various astrological organizations: to more objectively demonstrate to myself, my peers and the public generally, that I’m accountable to a code of ethics and will have reached a high standard of knowledge and practice. My certification with ISAR is pending, and I’m working on my certification with NCGR-PAA. Finally, I had a reason to buckle down and learn how to calculate a chart by hand.

As if I needed any more motivation, Deborah Houlding released her presentation on Whole Sign Houses. I don’t mean to reignite the whole controversy by mentioning it here, but I do want to acknowledge it as another source of motivation. Not only was I bewildered, disappointed and singularly unimpressed by her deluge of misrepresentations and historical falsehoods as well as her subsequent dishonesty and doubling down, but I was especially offended by her accusation that astrologers who use whole sign houses are “lazy”. Her words, not mine.

I was especially disheartened to see that many older astrologers on Facebook that I respect offered her explicit and tacit support, even as they also claimed they did not agree with her on every point. Upon further reflection I realized the rhetorical framing of whole sign houses as “lazy” was an appeal to grievance, especially to pre-software astrologers who had to calculate charts by hand with tables of houses, which likely ingrained an assumption that a house system must reach some arbitrary threshold of perceived complexity to be valid. Thus, Houlding was able to rhetorically conflate the erasure of mathematical barriers for chart calculation and the internet’s popularization of “dumbed down” pop astrology with the simplicity and popularity of whole sign houses when they’re actually separate developments.

This may not have been persuasive to every pre-software astrologer, but I can understand why it could be, because the grain of truth in there is that post-software astrologers have not had to calculate charts by hand, and so largely they don’t know how. Although I understood the abstract astronomical basis of different house divisions, I didn’t know how to actually calculate them myself. This is a problem that I could fix.

I learned how to calculate a natal chart through using Catherine Urban’s video course “Chart Calculations for the Apocalypse”. It’s not taught like a formal course with lectures, it feels more like hanging out with the cool/smart person in class who can explain things in a way that actually makes sense and holds your hand through each step. I had to make a little bit of an investment in buying atlases, ephemerides, tables of houses and a scientific calculator, but it really helped, and I highly recommend Catherine’s course if you’re interested.

So, can I calculate a natal chart by hand? Yes I can, even with “Placidus” divisions which I overlaid onto whole sign houses.

After posting this, I was called out for using a calculator. Challenge accepted.

Natal chart calculations are tedious and the steps must be followed exactly. You have to remember certain things depending on the quadrant of the globe the birth occurred and you kind of have to be aware of what you’re actually doing in each step. The math itself is not actually that hard, there’s just a lot of it. It also takes a lot of practice…

It can be very frustrating when you make a mistake and you’re not sure where or how. All of which are to be expected. What I didn’t expect was how the process of calculation moved me in the following ways:

  1. Intense gratitude for mathematicians, astronomers and astrologers of centuries past.
  2. Intense gratitude for astrological software developers of recent and current decades.
  3. Acute awareness of my privileged location in astrological history and intense gratitude for being born in this time.
  4. Deepened awareness of astrology as a distinctly Mercurial craft.
  5. Confidence that my practice of astrology is not dependent on astrological software.

Given all this, I was particularly struck by what Demetra George said recently on episode of the Astrology Podcast:

“We know that the ancient astrologers were called the mathematicians, the mathematico, and it was because they were always doing calculations. Now in the 1970s—I started my studies in 1970—the first thing that you had to do as an astrology student was to calculate the chart, and if you couldn’t do that there was no place else to go; you could not become an astrologer. There were no computer services or computer courses. And it was almost an initiation of sorts—to the extent that there’s a suggestion that astrology is an ancient mystery school teaching—then learning to calculate the chart is initiation number one in order to be able to enter the practice. And while it’s no longer necessary I think that it’s important, especially for all of us who want to support the memory of traditional astrology—the practice of it, the foundation of it—that that essential piece of it we likewise carry forward and pass on.

But even beyond that more lofty part, by the time you’ve done all the calculations and then you’ve created the chart and set it out—I remember having blank paper and a protractor and a compass to draw my 12-circled wheel and then put the house cusps in and put the planets in—I had an embodied connection with the chart. I knew it inside of me, on a deep level, before I ever saw the client. And so, I’m hoping that current astrologers—it’s unlikely that they’ll do all their charts by hand—but for them to have that experience. I think it’s an awesome thing to be able to say, as a traditional astrologer, “Yeah, I know this.” A very exhilarating moment.”
-Demetra George

One thing to read this, another thing to feel it. Especially as someone who has had a lifelong “psychological terror” of math, this felt like an accomplishment. Even though I’ve been in astrology now for ages, I feel in some way more complete for going through this long-delayed initiation ritual of manual chart calculation. I also feel some vindication in my own way of refuting the notion that Whole Sign House users are lazy. I also feel like this is my parting gift from Pluto in Capricorn before it goes into Aquarius. If Pluto in Aquarius is going to transport us headlong into the clouds of AI-assisted astrology, there’s something to be said for understanding astrology from the ground up while Pluto is still in Capricorn.

Is it necessary for an astrologer to know how to calculate a chart by hand? At this time and for the foreseeable future, no. Is it ideally better for an astrologer to know how to calculate a chart by hand? I think the answer is yes. Not just because of apocalyptic scenarios, but also as a way of deepening our understanding the mathematical underpinnings of our craft and to have a full appreciation and awareness of the privilege we have in using astrological software. Now that I’ve conquered some element of my fear of math, let’s enjoy this meme that could not make sense in literally any other context:

8 thoughts on “Should Astrologers Know How to Calculate Natal Charts by Hand?”

  1. I loved this article. It’s sad that kids are made to fee l they can’t do something, when usually it’s just that they haven’t been taught in the way that best suits them. I have my own stories like this so I heartily sympathise! I learnt how to cast my own chart many Moons ago, but have forgotten how to. I’d love to learn again, so thanks for the link.
    I’ve been really concerned too about the upcoming transits and how that will affect astrology – I’m a recent astrology graduate, hoping to have my own practise soon, so it would suck if the we see a repression of astrology in some way. But don’t get the impression anyone else seems concerned – so I appreciate your words and thoughts about this.

  2. Regarding the Saturn conjunction to Neptune in Pisces:

    I’m not sure it will result in hyperfocus on astrology particularly. I’m hoping it will bring scrutiny to the new age movement and religion as a whole. There’s a lot of harmful beliefs that have spread in the last few decades. Namely toxic positivity. Good events in life and the prosperity you receive are because you deserve them and are directly related to your thoughts. The inference being the bad things that happen are completely under your control as well. Does that mean the poor are lacking because they are somehow undeserving, negative people? I don’t think it’s coincidence that the popularity of this idea is most common in people that have benefited from generational wealth. It’s just extreme self-centeredness with a new age twist.

    There are those who believe that traumatic experiences were fated to happen because of past life misdeeds, or that your “soul” planned them before your birth to teach you some valuable life lesson. This is thinly disguised victim blaming. Any childhood development student could tell you positive reinforcement is many times more effective than negative. Anyone who thinks rape is a good way to teach someone a lesson is a psychopath in my opinion. It transfers the responsibility of the crime to the victim and away from the perpetrator, it’s gross and damaging.

    There are astrologers giving counseling when they are not a licensed mental health provider. And licensed professionals who employ a very toxic “forgiveness” Doctrine. Encouraging victims to forgive the perpetrator of their trauma, adding to the negative feelings towards themselves when they are understandably unable to. Often this is because of the counselor’s (astrologist) own religious/spiritual beliefs. Encouraging continued contact with harmful individuals when it’s not in the client’s best interest to do so.

    The best outcome of the Saturn transit would be to hold toxic positivity under a spotlight and expose it for what it really is.

    I could have gone deeper into this but I wanted to keep things short, I think it would be a good subject to explore on the astrology podcast. I’ve heard Leisa bring this up before and touch on it a little bit. These harmful beliefs are most often seen in the older generation of astrologists but have managed to carry over to some of the new ones as well. Luckily most of the new generation has come to question this very harmful and re-traumatizing line of thinking.

  3. I was totally hopeless at maths particularly numbers but .over geometry. So when I knew maths involved with learning astrology I was deflated but still began lessons and persevered. I began to understand if I’d miscalculated which helped when I had a computer and hit a wrong key number, as well as how time changed the ASCENDENT, HOUSES and degrees. I still have the notes, books etc showing the details. It also helped me understand I didn’t need a mercurial Mercury, just a Saturn to push my frustrations to final Eureka!

  4. Pingback: Calculating Astrology Charts by Hand - The Astrology Podcast

  5. Pingback: Calculating Astrology Charts by Hand -

  6. A thought-provoking exploration on the importance of calculating natal charts by hand! Your blog delves into the essence of astrological practice and the benefits of understanding the manual calculation process. The insights provided contribute to a deeper appreciation of the craft. Thanks for sharing your knowledge and sparking a meaningful conversation!

  7. Should Astrologers Know How to Calculate Natal Charts by Hand?” on Patrick Watson Astrology is a thought-provoking piece! Your discussion on the craft’s fundamentals adds a unique perspective to modern astrological practices. Thanks for delving into the intricacies and traditions of astrology. Eagerly awaiting more enlightening insights!

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