Hi Richard,

I use a similar calculator designed to convert to and from
metric.  Very handy item and shirt pocket size.  Found it at
an office supply store for about $20 some 4-5 years ago.
Its a Metric Converter model 830009 made by Sper Scientific.

I've seen converting calculators advertised in Ben Meadows
and Forestry Supply company catalogs -- they run about $48
and more.  Have also seen them at Wal-Mart and K-Mart stores
(less expensive) as well as an engineering supply house
(very expensive).

Lee Bennett
Bennett Management Services LLC
Monticello, Utah