According to this meta post, TI-BASIC is scored in tokens rather than characters, to more accurately reflect the byte count in-memory.
On my graphing calculator (TI-84 Plus C Silver Edition), the memory menu displays a slightly larger number than this would suggest. This number counts the length of the program name, and an apparent nine-byte header: an empty program with a one-letter name shows up as ten bytes in that menu. As such, I've been listing the length of my programs as
memory usage - length of program name - 9.
However, I recently realized that this "header" includes the first colon in a program, and as such I haven't been counting that. Should it be counted?
On one hand, it is part of the program text, and necessary headers in other languages generally count towards program length. On the other hand, in most other languages it is possible to give the compiler/interpreter a file without this header and you just get an error; for TI-BASIC, this leading colon cannot be deleted.