I found these mesurements posted a long time ago by another member. the original mesurements were in inches, and were estimated from props on display at the exhibition. I've converted them into cm.
A History Of Magic Dimensions: 1.5” x 6” x 12” (3.8 cm x 15.2 cm x 30.4 cm)
The Standard Book Of Spells Dimensions: 1.75” x 8” x 10” (4.4 cm x 20.3 cm x 25.4 cm)
Fantastic Beasts & Where to Find Them Dimensions: .4” x 7” x 9” (1.0 x 17.7cm x 22.8 cm)
Magical Theory Dimensions: 1.5” x 6” x 12” (3.8 cm x 15.2cm x 30.4cm)
Flying with the Cannons Dimensions: .5” x 9” x 13” (1.2 cm x 22.8 cm x 33.0 cm)
Quidditch Teams of England & Ireland Dimensions: 1.25” x 6” x 10” (3.1 cm x 15.2 cm x 25.4 cm)
Unfogging the Future volume I Dimensions: ⅔” x 8.5” x 13” Green, wide front, thin spine version (1.5 cm x 21.5cm x 33.0 cm)
Unfogging the Future volume V Dimensions: 1” x 6” x 8” Blue, small front, thicker version (2.5 cm x 15.2cm x 20.3 cm)
Magical Drafts and Potions Dimensions: ½-⅔” x 7” x 13” (1.2 cm x 17.7cm x 33.0 cm)
Advanced Potion Making (edition Four) Dimensions: 1”x 5” x 8” (2.5 cm x 12.7 cm x 20.3 cm)
Advanced Potion Making (Half-Blood Prince’s Copy) Dimensions: same as above
The Dark Forces: A Guide to Self Protection Dimensions: 2.75-3” x 7” x 11” (7.2 cm x 17.7cm x 27.9 cm)
Dark Arts Defense: Basics for Beginners Dimensions: 1” x 8” x 10” (2.5 cm x 20.3 cm x 25.4 cm)
The Life and Lies of Albus Dumbledore Dimensions: 1.25” x 8” x 12” (3.1 cm x 20.3 cm x 30.4 cm)
Gilderoy Lockhart Books:
Year With the Yeti Dimensions: .4-.5” x 9” x 8” (1.0 cm x 22.8 cm x 20.3 cm)
Travels With Trolls Dimensions: 1 ⅓” x 7” x 10” (3.3 cm x 17.7cm x 25.4 cm)
Magical Me Dimensions: 1 ⅔” x 6” x 9” (4.0 cm x 15.2 cm x 22.8 cm)
The Travel Trilogy Dimensions: 1” x 7” x 9” (2.5 cm x 17.7cm x 22.8 cm)
Break with the banshee Dimensions: ⅔” x 8” x 11” (1.5 cm x 20.3 cm x 27.9 cm)