The IB Diploma

"The marks awarded for each subject range from 1 (lowest) to 7 (highest). Students can also be awarded up to three additional points for their combined results on theory of knowledge and
the extended essay.

The full diploma is awarded to students who gain at least 24 points, subject to certain minimum levels of performance across the whole Diploma Programme and to satisfactory participation in creativity, action, service. The highest total that a Diploma Programme student can be awarded is 45 points."

-http://ibo.org/diploma/