The minimum points needed to get a place in certain high-demand college courses is expected to be up on last year.
First-round CAO offers will be sent out at two o'clock this afternoon.
When the calculated grades for this year's Leaving Cert were released on Monday morning, officials at the department of education said in spite of adjustments, this year's results were "stronger" than before.
The increase across the board is 4.4%, with students at higher level getting a bigger boost than those at ordinary level.
Registrar at Letterkenny IT and CAO board member Billy Bennett says the minimum cut-off for many courses will rise.
Officials have tried to counteract the points rise by opening 3,600 extra places this year.
That may ease pressure on some of the most competitive courses, like medicine, veterinary science and finance.
But it leaves around 20,000 students who are applying for the CAO this year with older Leaving Cert results at a disadvantage.
Meanwhile, a private grinds school in Dublin has claimed its students have been hit hard by the calculated grades process.
The Institute of Education says 96% of its 800 students have had a grade reduced - compared with 17% nationally.
