Inches or centimetres are fine for a book's dimensions. Measure the width, height and depth to determine the volume.
If you are talking about the length of the book's narrative, word count is probably the most accurate.
meeters?
Time
a millimeter
Millimetre.
The meter.
Centimeters
A kilometre.
Cm .
meeters?
Centimeters
Time
a millimeter
Millimetre.
always the meter to measure length. This is an SI (international) unit of measurment, and is the standard international unit of measurment for length.
Milligrams
the metric system
Kilometres