Tarot Birth Card Calculator

How tarot birth cards are calculated

The method comes from the tarot author Mary K. Greer, who set it out in Tarot Constellations (1987) and Who Are You in the Tarot? (2011). Here it is for a birth date of July 21, 1990.

1. Add the month, the day and the full year as ordinary numbers: 7 + 21 + 1990 = 2018.
2. Add the digits of that total: 2 + 0 + 1 + 8 = 11. A result of 23 or more has its digits added again; 22 stays as it is and stands for The Fool.
3. That number is your first card: 11 is Justice. If it has two digits, add them to reach the next card: 1 + 1 = 2, The High Priestess.

11 · Justice

2 · The High Priestess

Most dates give two cards this way. A total that reduces straight to a single digit gives one card, which holds both places. Only 19 gives three, because it reduces twice: 19 is The Sun, 1 + 9 = 10 is Wheel of Fortune, and 1 + 0 = 1 is The Magician.

What the two cards describe

Greer calls the higher number your Personality card and the single digit beneath it your Soul card. The Personality card describes how you tend to meet the world and the qualities you keep practising. The Soul card, the root number, is the theme underneath that keeps returning, whatever the season.

Read them as a lens to think with, not a verdict. The same pair can feel like a challenge at twenty and a resource at fifty, and neither reading is the final one.

Greer also groups the Major Arcana into constellations by their root number. A card that shares your root without being one of your birth cards is what she calls a hidden factor: part of the same family, and easier to overlook.

Two ways of adding up a birth date

This calculator follows Mary K. Greer, who adds the whole year as one number. The Tarot School's method, which several popular calculators also use, splits the year into two two-digit numbers instead. For July 21, 1990 it adds 7 + 21 + 19 + 90 = 137, then 13 + 7 = 20, and so gives Judgement and The High Priestess rather than Justice and The High Priestess.

That method always ends on a number from 10 to 21. A single digit is read with 9 added, so it never gives one card on its own, and never The Fool. For birth dates from 1950 to 2009 the two methods give the same result only about one time in eight. They always end on the same root, though, so your Soul card is the same either way. The calculator shows both results.

Every birth card result

The method can give twenty-one results. The share is of all birth dates from 1950 to 2009.

Why birth cards run in generations

The year is by far the largest number in the sum, so the digit sum drifts slowly with the calendar rather than jumping from one birthday to the next. Birth cards therefore cluster by generation: most people born in the 1930s share one handful of results, and most people born in the 1990s share another. The table shows the three most common results for each decade of birth.

Strength, Justice and Marseille decks

The method follows the Rider–Waite–Smith numbering, where Strength is 8 and Justice is 11. Tarot de Marseille decks number them the other way round: Justice is VIII and Strength is XI. If you read with a Marseille deck, a result of 17 and 8 pairs The Star with Justice, and 11 and 2 pairs Strength with The High Priestess.

More on the Marseille tradition

Questions about tarot birth cards