✛ Free Grand Cross Calculator: Is There One in Your Chart?

Umbriel's free Grand Cross calculator checks your birth chart for four planets forming a cross of two oppositions and four squares, and shows exactly how far each aspect is from exact.

A Grand Cross is four planets about 90° apart, so they make two oppositions crossing at right angles with a square between each neighbouring pair. It is a T-square with its fourth corner filled. The four planets usually sit in signs of one modality: a cardinal cross in Aries, Cancer, Libra and Capricorn, a fixed cross in Taurus, Leo, Scorpio and Aquarius, a mutable cross in Gemini, Virgo, Sagittarius and Pisces. Umbriel names the modality when all four share one.

Nothing in a Grand Cross is at rest: every planet is pulled two ways at once and no corner is easy. The classic reading is a chart that is always under load, and that people with one tend to be capable because they have had to be. The work, in that reading, is scheduling the tensions rather than resolving them. It is a description of a pattern of effort, not a prediction.

A Grand Cross is rare, and a tight one rarer. Because the outer planets move slowly, whole birth years can share one. The sky around the total solar eclipse of 11 August 1999 is the best-known recent case, and it is the worked example below.

Each aspect is judged on its own orb. Nothing is added up, the Sun and Moon get no extra orb, and the limits are the same for every planet. Every limit is at or below the orb the chart's own aspect lines use, so each aspect in a figure is also a line on your chart. Umbriel never widens an orb to produce a result. If nothing fits, the answer is none, and a figure that is only just outside an orb is shown on its own, marked as not counted.

In Umbriel's collection of 4,135 famous charts (born 1600 to 2014), cast for noon on the birth date with the Sun to Pluto and the Moon left out, because the collection holds no birth times, 18 have at least one Grand Cross at these orbs: 0.4 per cent.

At the wider orbs of the chart's own aspect lines (opposition 8°, trine and square 7°, sextile 5°, quincunx 3°), 31 would have one: 0.7 per cent instead of 0.4. The orb choice alone moves the answer, which is why this page prints its own.

That is a count of famous people, not of births: the collection leans towards the twentieth century, and because Jupiter to Pluto move slowly, a whole birth cohort can share a figure made of them. A fair sample of everyone would differ.

Umbriel casts the ten planets, Sun to Pluto, for the moment of birth with the same engine as the rest of the app, then tests every combination of planets against the shape. A figure counts only if every aspect in it is inside its own orb: opposition 6°, and square 6°. Each aspect is judged on its own orb. Nothing is added up, the Sun and Moon get no extra orb, and the limits are the same for every planet. Every limit is at or below the orb the chart's own aspect lines use, so each aspect in a figure is also a line on your chart.

The Ascendant and Midheaven are left out because they need an exact birth time and place; the lunar nodes, Chiron and the asteroids are left out to keep one clear rule. Adding any of them would find more patterns, and every pattern found that way depends on a choice that is not made here. Umbriel never widens an orb to produce a result. If nothing fits, the answer is none, and a figure that is only just outside an orb is shown on its own, marked as not counted.

The place of birth does not matter for this, because the planets stood at the same longitudes wherever you were born. What turns your clock time into a moment is the time zone, which is why the form asks for a UTC offset and not a city. Use the offset that was in force on the birth date, daylight saving included. The place of birth does not change where the planets were, so Umbriel asks for the time zone, not the town.

With no birth time the Moon is the first thing to move. The Moon travels about 13° a day, so with no birth time it could have stood anywhere in a span of about 26°, and any figure that includes it depends on the hour. The Ascendant and Midheaven need an exact time and place, so Umbriel does not use them here at all.

Not a person's chart but a famous sky: 11 August 1999, about 11:03 UT, the total solar eclipse that crossed Europe. All ten planets, the Moon included, are in the sky at that moment, and Umbriel finds 2 Grand Crosses:

Moon, Mars, Uranus and Saturn, all in fixed signs

Moon 18°18′ Leo, Mars 16°50′ Scorpio, Uranus 14°40′ Aquarius, Saturn 16°53′ Taurus.

• Moon opposite Uranus3°38′ from exact, limit 6°
• Mars opposite Saturn0°02′ from exact, limit 6°
• Moon square to Mars1°28′ from exact, limit 6°
• Mars square to Uranus2°10′ from exact, limit 6°
• Uranus square to Saturn2°12′ from exact, limit 6°
• Saturn square to Moon1°25′ from exact, limit 6°

Sun, Mars, Uranus and Saturn, all in fixed signs

Sun 18°21′ Leo, Mars 16°50′ Scorpio, Uranus 14°40′ Aquarius, Saturn 16°53′ Taurus.

• Sun opposite Uranus3°41′ from exact, limit 6°
• Mars opposite Saturn0°02′ from exact, limit 6°
• Sun square to Mars1°31′ from exact, limit 6°
• Mars square to Uranus2°10′ from exact, limit 6°
• Uranus square to Saturn2°12′ from exact, limit 6°
• Saturn square to Sun1°28′ from exact, limit 6°

There are two because it was a New Moon: the Sun and Moon stood within a degree of each other, so each makes the same cross with Mars, Uranus and Saturn. Anyone born that week has one, with the Moon's place depending on the hour.

Because the Moon is in one of them, a birth on that day would need its time to know which of the two shapes it carries, though the Sun's version holds all day.