Could be a case of data inconsistency,
ie some of the times are "text" times ..

Instead of using eg: =SUM(A2:A5)
Try a gentle coercion via SUMPRODUCT, viz.:
=SUMPRODUCT(--(A2:A5))

with the formula cell custom formatted as: [h]:mm
--
Max
Singapore
http://savefile.com/projects/236895
xdemechanik
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"Sam" wrote:
What is the secret to adding-up time? I have my cells set for [h]:mm and
when I sum the column the total of wrong. What am I missing?
Thanks!