Tool to convert Cistercian numbers (read / write monks cipher/numbers of cistercian monks into Arabic numerals) used in the Middle Ages (also called cipher of the monks).
Cistercian Monk Numerals - dCode
Tag(s) : Numeral System, Symbol Substitution
dCode is free and its tools are a valuable help in games, maths, geocaching, puzzles and problems to solve every day!
A suggestion ? a feedback ? a bug ? an idea ? Write to dCode!
Cistercian Monk Numerals
Conversion of Cistercian Numbers
Convert to Cistercian Number
Answers to Questions (FAQ)
What are cistercian numbers? (Definition)
The Cistercian numeration was recently discovered. Used by Cistercian monks at the end of the Middle Ages, it makes it possible to write numbers between 0 and 9999 using a drawing made up of a vertical bar and a few lines.
How to write a number with cistercian monks cipher?
The numeral system of Cistercian monks uses a quadrant (in 4 parts) to represent numbers from 0 to 9999.
Any number necessarily consists of a central vertical bar, if nothing else is written, then it takes the value 0, otherwise, the quadrant at the top right corresponds to the units, the quadrant at the top left for the tens, the quadrant at the bottom right for the hundreds and the last quadrant at the bottom left for the thousands.
There are then 9 symbols to represent the numbers (here the units):
| 1 | .png) | 2 | .png) | 3 | .png) |
| 4 | .png) | 5 | .png) | 6 | .png) |
| 7 | .png) | 8 | .png) | 9 | .png) |
Rotate/mirror these symbols to write them in the right quadrant.
Example: 5555 is written 
How to read/convert a cistercian number to arabic number?
Decompose the symbol in 4 quadrants and find the corresponding figure for the thousand (bottom left), hundreds (bottom right), tens (top left), units (top right).
Example: 
is read 3579
How to write a decimal number (with decimal places)?
Research has not shown the existence of decimal numbers among the traces left by monks.
How to recognize a cistercian monk cipher/numbers?
Numbers are composed of line-based symbols in 4 corners.
All references to the Cistercian order and the (french) monks are clues.
This numeral system was popularized by David A. King's book entitled The Ciphers of the Monks: a Forgotten Number-notation of the Middle Ages
When was this cistercian numeral system invented?
The cistercian numeral system seems to have been created around the 14th century.
Source code
dCode retains ownership of the "Cistercian Monk Numerals" source code. Any algorithm for the "Cistercian Monk Numerals" algorithm, applet or snippet or script (converter, solver, encryption / decryption, encoding / decoding, ciphering / deciphering, breaker, translator), or any "Cistercian Monk Numerals" functions (calculate, convert, solve, decrypt / encrypt, decipher / cipher, decode / encode, translate) written in any informatic language (Python, Java, PHP, C#, Javascript, Matlab, etc.) or any database download or API access for "Cistercian Monk Numerals" or any other element are not public (except explicit open source licence like Creative Commons). Same with the download for offline use on PC, mobile, tablet, iPhone or Android app.
Reminder: dCode is an educational and teaching resource, accessible online for free and for everyone.
Cite dCode
The content of the page "Cistercian Monk Numerals" and its results may be freely copied and reused, including for commercial purposes, provided that dCode.fr is cited as the source.
Exporting the results is free and can be done simply by clicking on the export icons ⤓ (.csv or .txt format) or ⧉ (copy and paste).
To cite dCode.fr on another website, use the link:
In a scientific article or book, the recommended bibliographic citation is: Cistercian Monk Numerals on dCode.fr [online website], retrieved on 2025-04-24,
- Conversion of Cistercian Numbers
- Convert to Cistercian Number
- What are cistercian numbers? (Definition)
- How to write a number with cistercian monks cipher?
- How to read/convert a cistercian number to arabic number?
- How to write a decimal number (with decimal places)?
- How to recognize a cistercian monk cipher/numbers?
- When was this cistercian numeral system invented?
