Excel Power Expander’s “Units Conversion” is a very flexible
utility for converting numbers from one measurement system to another. For
example, it can translate a table of distances in miles to a table of distances
in kilometers.

Units Conversion translates the following units :

Weight
and mass

Distance

Gram "g"
Slug "sg"
Pound mass (avoirdupois) "lbm"
U (atomic mass unit) "u"
Ounce mass (avoirdupois) "ozm"

Meter "m"
Statute mile "mi"
Nautical mile "Nmi"
Inch "in"
Foot "ft"
Yard "yd"
Angstrom "ang"
Pica (1/72 in.) "Pica"

Time

Pressure

Year "yr"
Day "day"
Hour "hr"
Minute "mn"
Second "sec"

Pascal "Pa"
Atmosphere "atm"
mm
of Mercury "mmHg"
Bar "bar"

Force

Energy

Newton "N"
Dyne "dyn"
Pound force "lbf"

Joule "J"
Erg "e"
Thermodynamic calorie "c"
IT calorie "cal"
Electron volt "eV"
Horsepower-hour "HPh"
Watt-hour "Wh"
Foot-pound "flb"
BTU "BTU"