Interesting timings there, Bernd ! Thanks.

Wonder how these comparative timings would look like if we were to say cover
20000 rows instead, and with error trapping* included for your/TM's
suggestions? *see below.

Copy down until you see error values...
Ahh, but my suggestion also eliminates all those nasty error values, giving
neat outputs for the OP <g
--
Max
Singapore
http://savefile.com/projects/236895
xdemechanik
---
"Bernd P" wrote in message
oups.com...
Hello,

Another approach:
Enter into E2:
=MATCH(1,B2:$B$65536,)+1
Enter into E3:
=MATCH(1,INDEX(B:B,E2+1):$B$65536,)+E2
Copy down until you see error values...

Calculation times for 2000 rows with 115 "one"s: 0.65 millisecs
[Max': 48.77 millisecs where column D took 45.48ms]

Regards,
Bernd