Useful information to help in breaking codes.
The table below shows how often each letter appears in standard English writing.
This is based on looking at thousands of pieces of writing in English and is a good rough guide.
| A | B | C | D | E | F | G | H | I | J | K | L | M |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 8.2% | 1.5% | 2.8% | 4.3% | 12.7% | 2.2% | 2.0% | 6.1% | 7.0% | 0.2% | 0.8% | 4.0% | 2.4% |
| N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
| 6.7% | 7.5% | 1.9% | 0.1% | 6.0% | 6.3% | 9.1% | 2.8% | 1.0% | 2.4% | 0.2% | 2.0% | 0.1% |
The figures are taken from the Wikipedia article on letter frequency.
If your text is split into words it can be useful to know which letters are most likely to appear at the start of a word in English.
The seven letters which are most likely to start words in English are:
| Letter | Frequency |
|---|---|
| T | 16.7% |
| A | 11.6% |
| S | 7.8% |
| H | 7.2% |
| W | 6.8% |
| I | 6.3% |
| O | 6.3% |
The least frequent letters to start words with in English are z, x and q.
It can also be useful to know that the letters most likely to appear as double letters in English words are: LL; EE; SS; OO; and TT.
If you're seeing double letters in your code then you might be able to use this knowledge to help you crack the code.