Bob Phillips wrote

For i = 1902 to 4 Step - 19
Range("B" & i).Formula = "SUM(AB" & i - 18 & ":AB" & i-1 & ")"
Next i

Put your loop controls, start and step, in variables and you are away.

Excellent. I had to put an = in front of SUM (or result was text) and
change 18 to 17 (so student name row wasn't included), but then it worked
perfectly and surprisingly fast.

Thanks.

--
David