Chaldean vs Pythagorean: which letter system to use

The Chaldean and Pythagorean systems are the two ways of turning letters into numbers, and they do not agree with each other. Chaldean values letters by sound and never uses 9; Pythagorean numbers the alphabet in order from 1 to 9 and repeats.

How does the Chaldean table work?

The Chaldean table groups letters by the sound they make, following, by tradition, an old Hebrew and Babylonian correspondence. A, I, J, Q and Y are 1; B, K and R are 2; and so on. No letter is 9. The compound number (the total before reduction) matters as much as the final digit in Chaldean readings.

You can see the sound principle in the groups. The groups do not follow alphabetical order: D, M and T sit together at 4, and F and P share 8, letters that are far apart in the alphabet. Practitioners explain the groupings by vibration and sound rather than position, which is why Chaldean is described as a sound-based system. The table is fixed, though: it gives one value per English letter, and the calculator applies it letter by letter without any judgement about pronunciation.

Why does Chaldean leave out 9?

Tradition holds that 9 is complete and sacred, the number that contains all the others, so it was kept apart from the letters. There is an arithmetic echo of this idea: adding 9 to any number never changes its reduced digit (4 + 9 = 13, and 1 + 3 = 4), so 9 behaves as a number that holds everything without altering anything. A name can still total 9, or reduce to it; only single letters never carry it.

How does the Pythagorean table work?

The Pythagorean table is mechanical: A is 1, B is 2, up to I which is 9, then J starts again at 1. Every letter has a value and the final digit is what counts. Western practice also gives special weight to master numbers 11, 22 and 33 when a total lands on them, and builds extra numbers from parts of the name, for example from the vowels alone. This site does not calculate those vowel and consonant numbers; it reads the whole name.

Value	Chaldean	Pythagorean
1	A, I, J, Q, Y	A, J, S
2	B, K, R	B, K, T
3	C, G, L, S	C, L, U
4	D, M, T	D, M, V
5	E, H, N, X	E, N, W
6	U, V, W	F, O, X
7	O, Z	G, P, Y
8	F, P	H, Q, Z
9	none	I, R

Worked example: the same name, two answers

PRIYA in Chaldean: P8 + R2 + I1 + Y1 + A1 = 13 → 1 + 3 = 4.

PRIYA in Pythagorean: P7 + R9 + I9 + Y7 + A1 = 33 → 3 + 3 = 6, and 33 is a master number.

Same name, two different numbers and two different stories. Neither is wrong; they are different systems, and a reading should say which one it used.

A second example: a full name

Most people are known by more than one word, and the calculator adds every letter of every word. It also shows each word's own total, which is useful when you want to see what the first name and the surname contribute. Take SUNIL KUMAR.

Word	Chaldean	Pythagorean
SUNIL	3+6+5+1+3 = 18	1+3+5+9+3 = 21
KUMAR	2+6+4+1+2 = 15	2+3+4+1+9 = 19
Total	18 + 15 = 33 → 6	21 + 19 = 40 → 4

Step by step in Chaldean: S3, U6, N5, I1, L3 give 18; K2, U6, M4, A1, R2 give 15; the full total is 33, which reduces to 3 + 3 = 6. Because the full total is exactly 33, the result card also shows the master number note. In Pythagorean the total is 40, which reduces to 4 + 0 = 4, with no master number.

So the same person reads as a 6 (Venus: care, harmony) in one system and a 4 (Rahu: method, structure) in the other. This is the clearest reason never to borrow a number from one system and a meaning from the other.

Common mistakes

• Mixing systems. Working out a name in Pythagorean from a Western website and then reading it with Indian planets gives a reading that belongs to neither tradition.
• Writing I as 9 in Chaldean. It is the most common slip when people switch tables by hand. In Chaldean, I is 1.
• Changing the spelling between readings. LAKSHMI is 19 → 1 in Chaldean, while LAXMI is 14 → 5. Both spellings are valid; they are simply different strings of letters. Use the spelling you actually write.
• Typing the name in Devanagari. Both tables are defined for the 26 English letters, so the calculator asks for the name in its usual English spelling.
• Assuming one system is more accurate. Each is internally consistent. The choice is about which tradition you are reading in, not which one is true.

Chaldean or Pythagorean at a glance

Point	Chaldean	Pythagorean
How letters are valued	By sound, in fixed groups	By position in the alphabet
Is 9 used for letters?	No	Yes (I and R)
Compound readings	Central (totals 10 to 52)	Not part of the Western method
Ruling planets	Yes, in Indian practice	No
Where you will meet it	Indian practitioners, Hindi books	Western books and websites

Which should you use?

Use Chaldean if you follow Indian numerology, want the planets and compound readings, or are reading with an Indian practitioner. Use Pythagorean if you are following a Western book and want your numbers to match it. Do not mix them in one reading. This site defaults to Chaldean and lets you switch with one tap; master number notes appear in both. The card also shows the compound reading for a Pythagorean total, but that reading comes from the Chaldean list, so give it less weight there. The next step is lesson 8 on name numbers and compound numbers, which explains how a name total is read once you have it.

Calculate yours

Try the calculator this lesson explains.

Full name

English letters only, for example Rahul Sharma

Letter system

Chaldean (Indian)Pythagorean (Western)

Date of birth (optional, for the match with your numbers)

Day

Month

Year

For example 14 08 1990 · Remembered on this device only, never sent anywhere.

Calculate