One way:

With Range("C1:C50000")
.Formula = "=A1+B1"
.Value = .Value
End With

In article ,
jonigr wrote:

This simple routine has crept into my code and I use it thoughtlessly and
often:

For i = 1 To 50000 ' some seriously large value here!
Range("C" & i).Value = Range("A" & i).Value + Range("B" & i).Value
Next i

I discovered it is a time-consumer, searched for alternatives and found
several, but am just not VBA fluent enough to judge their efficiency.

Any more experienced programmers can help me find the truly fastest solution?

Thanks!

-Joni