MeaSure is a simplified
unit-conversion utility you can use to calculate values between a wide range
of different standard units. It will convert over 120 different
measurements, grouped in 12 general categories, including Length, Area,
Volume, Capacity (fluid & dry), Mass, Speed, Temperature, Work, Power,
Pressure, and Numbers. Once the values you need are converted, the answer
can be copied/pasted to the Clipboard for transfer to another application.
MeaSure is simple to use and easy to navigate and offers a multilingual
interface with text entries shown in four different languages (English,
Italian, German, or Spanish).

meaSure is the Shareware version. The full version can be purchased by clicking on the "CLICK HERE TO ORDER" button below for around  6USD.