How many three letter combinations are there?
26 Ã— 26 Ã— 26 = 17,576
The total number of possible three-letter abbreviations using the 26 letters of the alphabet from A to Z (AAA, AAB, AAC, AAD, AAE, AAF, AAG, AAH, AAI, AAJ, AAK, AAL, AAM, AAN … to ZZY, ZZZ) is 26 Ã— 26 Ã— 26 = 17,576. Not too many people know that another 26 Ã— 26 Ã— 10 = 6760 can be produced if the third element is allowed to be a digit 0-9, giving a total of 24,336. The three letter combination is also called three-letter acronym, three-letter abbreviation or TLA.