Free T-square calculator

You very likely have a T-square. How tight is yours?

About 86 in 100 charts have a T-square, so the answer to “do I have one?” is nearly always yes. What's worth knowing is how tight yours is, and which parts of you it ties together. Enter your birth details and we'll measure it.

This is just one shape. Your whole chart shows you your birth chart drawn out, your Sun, Moon and rising sign, and the one shape in your chart that is most worth a closer look.

See your whole chart

Also in your chart

Here is the same check for the other shapes. You can open any of them to see yours in detail.

If you'd like a reading, the options are at the bottom of this page.

Would you like to look closer?

A reading is created from the whole of your chart, not just one shape. Your birth details are already here, so the form below takes you straight to a secure payment page.

It arrives in a private learning portal, with a chat function you can ask about it. If you are not sure what a reading looks like, you are welcome to read three chapters from a real one, which is my own.

Your reading · ~~usually £90~~ £60 special offer An in-depth reading of every part of your chart and how they work together, chapter by chapter, with diagrams drawn from your chart. It includes the areas of your life, such as home, work, money and partnership. The full unlock · £180 Your reading tells you what your chart holds, and this takes you into it. It is your reading, the areas of your life included, with what's live for you now added. The planets have kept moving since you were born, and as each one passes over a place in your chart, that part of you tends to come to the front for a while. This looks at the next six months and shows which parts of your chart are being reached, how closely, and when. As each date arrives, you can check it against your own life. It comes with a practice companion: guided practices drawn from your own reading. If you have already paid for a reading, what you paid is taken off the £180. This one is made to order, so there's nothing to pay now and I'll reply by email.

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Send the birth details above with my request, to be stored securely and used only to prepare it.

You'll be taken to a secure Stripe page to pay £60 by card. Your reading is delivered within 7 days of my starting it, and you can cancel for a full refund within 14 days of paying, until I start. The terms cover cancelling and refunds.

If you'd like to ask me something first, you're welcome to get in touch.

What is a T-square?

Two points in a chart sit opposite each other (180°), and both sit square (90°) to a third, called the apex. Drawn on the wheel it makes a right-angled triangle across half the chart. The empty point opposite the apex is often called the missing leg.

Two parts of you pull in opposite directions, and both press on a third, which ends up carrying the strain of the pair. Astrologers call this shape a T-square. Most charts have at least one, so having one isn't the point. What matters is which three parts of you it binds together, and how tightly.

It tends to feel like a low, steady sense that something is still open, even on a good day. The third part, where the pressure lands, often becomes the busiest part of a life, because it's where the pull between the other two gets worked out. That's usually where effort turns into ability over the years. The pull itself rarely settles, and it doesn't need to. It tends to ease once you stop reading it as a sign that something is wrong with you.

How common is a T-square?

Almost every chart has one. Here's how often it turns up, and how quickly that changes as the sides get tighter, measured across 100,000 random birth charts from 1930 to 2025:

T-square	Charts with one
Any T-square, at the orbs usually allowed	86 in 100
Every side within 2°	24 in 100
Every side within 1°	8 in 100
Every side within half a degree	2 in 100

We count the planets, the Moon's nodes, Chiron, the Part of Fortune, the Vertex and the angles, which is one reason the shape is so common. The tighter the sides, the less common it gets, which is what the figure in your result measures.

Questions

Is a T-square rare?

No, it's very common. Measured across 100,000 random charts, about 86 in 100 have at least one T-square at the usual orbs. A tight one is different, though, because about 2 in 100 have one with every side within half a degree. That's why this calculator measures yours instead of just finding it.

What is the apex of a T-square?

It's the point that both ends of the opposition square. The pull between the other two lands there, so it's usually the first part of the shape to read. Your result names the apex and the points it joins.

What does "1 in X charts have one this strong" mean?

We scored a million random charts the same way as yours and counted how many have a T-square at least as tight, and the figure is that share. Below about 1 in 20 we use a word instead of a number, because a figure that small doesn't tell you much.

What if I don't know my birth time?

The calculator still works, but a T-square that involves your Moon or your rising sign can't be placed, because both move too far in a day. If that's possible for your chart, it tells you it can't be sure, rather than saying no.