Hillary needs something around 57% or 58% of the remaining delegates. Honestly I really don't think Sanders will be too far behind whenever Hillary reaches the number to clinch the nomination.
??? Wait, explain this math to me... she already has a lead in delegates. Why would she need to have a majority of remaining delegates to keep the lead? Couldn't she have less than 50% and still maintain the lead?
Are you sure you aren't mixing up Clinton and Sanders?