Following a thread from last week I used this online rating calculator
http://www.maskeret.com/mecca/elo_fide.htm with these values (from ICC)

Your initial ELO 2619
Your K coefficient 10
Your score 7.5
Tournament Type R
Your opponents ELO 2525 2495 2511 2589 2511 2381 2393 2432 2245

And it gave these results

Average ELO Opponents 2470
Expected score (We) 6.3
Difference Score - Expected 1.2
Difference in ELO points 12
Rounded difference 12
Your New ELO 2631
*Performance 2726*

IIRC this was his third good tournament performance in quick succession.
Luke seems to be fulfilling his (very) early potential.

cheers

dd