If anyone is still following this thread I'll do some tests and post the
results. Stay tuned!

Biff

"Pete_UK" wrote in message
ups.com...
Max,

The OP didn't get back to me when I asked about sorting the reference
data beforehand. Can you sort your random data in the 6 sheets then
re-apply your formula to take advantage of this to see if there is a
big increase in speed? In theory, the binary search technique applied
if the data is sorted should make a massive difference to 6 * 65536
entries.

Pete