Grant,

You can make cells yielding negatives appear as 0 with formatting. Format -
Cells - Number - Custom tab:

General;"0";0

Or nothing:

General;;0

This is for display only; the formula will still be yielding a negative
value, and any formulas referring to the cell will not get 0, but the true
(negative) value. In that case, modify the formula to not yield a negative
value, as per JMB's post.
--
Earl Kiosterud
www.smokeylake.com
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"grant" wrote in message
...
I would like calcualed vales in cells to =zero if the calculation result is
negative/blow zero. In other words a threshold that values below zero are
not
produced.