Reading the code14M-1400-55 is a 14M belt with a 1400mm pitch length and a 55mm width. Some brands write it the other way round, such as 1400-14M-55 or 55-14M-1400, but the numbers mean the same thing.
Counting teethPitch length divided by 14mm gives the tooth count, so a 1400mm 14M belt has 100 teeth. If the code has worn off, count the teeth and multiply by 14 for the length.
HTD or Supertorque?Supertorque S14M belts have the same 14mm pitch but a different tooth shape. They need their own pulleys, so check the tooth profile before swapping.