How to Calculate Your Tarot Birth Cards
Follow a worked example of the century-split method, with clear rules for single-digit results and the three-card exception.
Start with four parts
Write the month, day, first two digits of the year, and last two digits of the year. Add these four numbers. For the public example February 21, 1950: 2 + 21 + 19 + 50 = 92. For years in the 2000s the century component is 20.
Reduce once before choosing a card
A two-digit total is reduced by adding its digits: 92 becomes 9 + 2 = 11. If the total has three digits, add the first two as a whole number to the last digit. The public example August 20, 1969 totals 116, so calculate 11 + 6 = 17, rather than adding three individual digits.
Keep the group together
A first reduction from 10 through 21 is retained as the high card. Reduce its digits to find its companion: 11 becomes 2, giving Justice and the High Priestess. A reduction reaching 19 keeps the complete chain 19 → 10 → 1: Sun, Wheel of Fortune, and Magician.
When the first reduction is one digit
Use the paired-card lookup: 1 pairs with 10, 2 with 11, 3 with 12, and so on through 9 with 18. This is a lookup, not another arithmetic step. For October 23, 2000, the total 53 reduces to 8; the matching high card is 17, giving Star and Strength.
Our explicit boundary rules
If the three-digit operation produces 22 or 23, reduce again to 4 or 5 and use the lookup, giving 13/4 or 14/5. The Fool is numbered 0 and is not a result. Raw total 21 first reduces to 3 and gives 12/3; total 129 first reduces to 21 and gives 21/3. The stage at which a number appears matters.
Check the method, not just the final digit
The calculator shows the same steps described here, including any lookup. Use the full group when reading a result. These are deterministic symbolic associations, not a scientific measurement of personality. The sources below document the method; the boundary policies above make our implementation explicit.