Open data
Letter to number tables, Pythagorean and Chaldean
The numeric value of each letter in both numerology systems, with the convention for Vietnamese diacritics and the letter D with stroke.
33 rows · 7 columns · version 1.0.0 · updated 2026-09-21
Conventions taken
THIS IS THE POINT WHERE EVERY VIETNAMESE TOOL DIFFERS, so publishing it plainly creates a reference to check against, not a rule to impose. Three disagreements. First, the letter D with stroke: this table maps it to D, while some tools map it to DD and the number then differs entirely. Second, the letter Y: this table treats it as a consonant, while some schools treat it as a vowel between consonants, which changes the Soul Urge and Personality numbers but not the Expression number. Third, the two systems give different numbers for the same name, and that gap is REAL: Pythagorean assigns 1 to 9 in alphabetical order, while Chaldean assigns ancient values and uses no 9 at all, holding that number sacred. Vietnamese numerology uses almost only Pythagorean; Chaldean is here so anyone comparing two sources understands why they differ.
| id | chu | pythagoras | chaldean | nguyen_am | nguon | ghi_chu |
|---|---|---|---|---|---|---|
| A | A | 1 | 1 | co | tinh-toan | |
| B | B | 2 | 2 | khong | tinh-toan | |
| C | C | 3 | 3 | khong | tinh-toan | |
| D | D | 4 | 4 | khong | tinh-toan | |
| E | E | 5 | 5 | co | tinh-toan | |
| F | F | 6 | 8 | khong | tinh-toan | |
| G | G | 7 | 3 | khong | tinh-toan | |
| H | H | 8 | 5 | khong | tinh-toan | |
| I | I | 9 | 1 | co | tinh-toan | |
| J | J | 1 | 1 | khong | tinh-toan | |
| K | K | 2 | 2 | khong | tinh-toan | |
| L | L | 3 | 3 | khong | tinh-toan | |
| M | M | 4 | 4 | khong | tinh-toan | |
| N | N | 5 | 5 | khong | tinh-toan | |
| O | O | 6 | 7 | co | tinh-toan | |
| P | P | 7 | 8 | khong | tinh-toan | |
| Q | Q | 8 | 1 | khong | tinh-toan | |
| R | R | 9 | 2 | khong | tinh-toan | |
| S | S | 1 | 3 | khong | tinh-toan | |
| T | T | 2 | 4 | khong | tinh-toan | |
| U | U | 3 | 6 | co | tinh-toan | |
| V | V | 4 | 6 | khong | tinh-toan | |
| W | W | 5 | 6 | khong | tinh-toan | |
| X | X | 6 | 5 | khong | tinh-toan | |
| Y | Y | 7 | 1 | khong | tinh-toan | Vài phái coi Y là nguyên âm khi nó đứng giữa hai phụ âm; bảng này xếp Y là phụ âm |
| Z | Z | 8 | 7 | khong | tinh-toan | |
| Đ | Đ | 4 | 4 | khong | tinh-toan | Quy về D. Vài công cụ Việt quy Đ về DD và khi ấy con số lệch hẳn |
| Ă | Ă | 1 | 1 | co | tinh-toan | Quy về A, bỏ dấu |
| Â | Â | 1 | 1 | co | tinh-toan | Quy về A, bỏ dấu |
| Ê | Ê | 5 | 5 | co | tinh-toan | Quy về E, bỏ dấu |
| Ô | Ô | 6 | 7 | co | tinh-toan | Quy về O, bỏ dấu |
| Ơ | Ơ | 6 | 7 | co | tinh-toan | Quy về O, bỏ dấu |
| Ư | Ư | 3 | 6 | co | tinh-toan | Quy về U, bỏ dấu |
What the columns mean
id(string)- Stable row identifier, unchanged across versions
chu(string)- Letter, uppercase
pythagoras(int)- Value in the Pythagorean system, 1 to 9
chaldean(int)- Value in the Chaldean system, 1 to 8; that system uses no 9
nguyen_am(string)- co when this character is a vowel, used to calculate the Soul number
nguon(string)- Source text for this row, or tinh-toan when the value is computed
ghi_chu(string)- Where the schools disagree on this row; empty when they do not
Licence and limitations
Released under CC BY 4.0: reuse commercially, adapt freely, attribution is all that is asked.
Nguồn: Nhật Nguyệt (nhatnguyet.org), CC BY 4.0
This dataset records cultural and calendrical conventions, not scientific claims. It is suitable for cultural research, NLP, and calendar applications. It is not intended for predicting events, evaluating people, or making decisions that affect anyone.
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