BED start is 0-based BED end is 0-based, but exclusive Therefore, the fist 100 bp of a chromosomes have start 0 and stop 100 and include bases 0-99! [Source](http://genome.ucsc.edu/FAQ/FAQformat.html#format1)
BED start is 0-based
BED end is 0-based, but exclusive
Therefore, the fist 100 bp of a chromosomes have start 0 and stop 100 and include bases 0-99!
Source