LOOKUP would be the best *BUT* the data *MUST* be sorted in ascending order
and if there isn't an exact match LOOKUP will find the next lowest item.
This isn't optional like it is with VLOOKUP or INDEX/MATCH.

After LOOKUP, INDEX/MATCH would be the next best option.

Also note that if your data is sorted VLOOKUP can be a lot faster than when
the data is not sorted.

--
Biff
Microsoft Excel MVP


"PYO1012" wrote in message
...
I have data that's 50 some odd columns wide and about 500 rows deep. Is
there a more efficient method of looking up values using either a LOOKUP
function or an INDEX function? I'm asking because I notice Excel starts
to
lag when I use VLOOKUP with such a large amount of data and I want to know
if
it would be worth my time changing it to a INDEX/MATCH funtion. Does one
or
the other work quicker?