How is NBDE score calculated?

A candidate's total score is computed using the total number of correct answers selected by the candidate. The total score is then converted to a scale score, which adjusts for any minor differences in difficulty across NBDE Part I forms.

What score is needed to pass the Nbdhe?

The status of “pass” is granted if you achieve a standard score of 75 or higher. A candidate's total score is calculated by the total number of correct answers selected by the candidate, which is adjusted for any minor differences in difficulty across NBDHE forms (i.e., scaled).