In each unit you can find formulae, conversion tables and unit conversion indexes. The first gives you the exact way of transforming one unit to another, the second gives you equivalent of main units and the third allows you to refer quickly to the tables you can find the units of measurements.

The book is so versatile because it enables you to make rough estimates without using any calculator. On the other hand, however, if you want to be 100% precise, you can count on the numerous formulae in the book to make exact calculations.

I strongly recommend this book anyone who wants to be able to understand both metric and imperial systems, and wants to have a reliable reference book at the same time.