Which is cheaper?
To know the answer, one must be able to convert between different mass and weight units and also between the current exchange rates for international currencies. This library of calculators makes these and many more calculations trivial by letting you choose your units (length, area, volume, weight and even currency), enter your numbers and get a reliable answer.
NOTE: The default currency is U.S. dollars (USD). However, the user can choose and automatically convert other currencies via the pull-down menu.