Looking up cell data and showing results from adjoining cell

Good evening,

I would like to be able to enter the data into the grey cells and then have the yellow cells auto generate a result. The only problem is that the required value in cell B5 is from when the entered value in B4 is looked up in the table, rounded UP to the next highest value and then the answer from the next cell.

So, if I enter in B4 a value of 500, a lookup is made in the table and the next highest value would be 553 with the correct answer shown in B5 being 13.

Thank you in advance for any help that can be offered.