Complete size calculation does not match

I checked the build size in the editor log, but complete size does not match from the sum of all.

Textures      6.4 mb	 9.6% 
Meshes        0.0 kb	 0.0% 
Animations    60.0 kb	 0.1% 
Sounds        2.2 mb	 3.3% 
Shaders       339.8 kb	 0.5% 
Other Assets  3.1 mb	 4.6% 
Levels        13.6 mb	 20.4% 
Scripts       1.5 mb	 2.2% 
Included DLLs 3.9 mb	 5.9% 
File headers  225.0 kb	 0.3% 
Complete size 66.6 mb	 100.0% 

In my calculation complete size will be 31mb.
What is the rest 35mb?

Unity Version: 5.5.2f1 Personal

Building for iOS and Android.

That’s simply the engine’s core. You have ignored the percent information given in the listing. Those add up to about 46.9%

66.6 * 46.9 / 100 == 31.2354

So everything listed here is correct, it just don’t list certain overhead explicitly. “Scripts” only covers your own scripts. The actual engine is not covered in this listing. This is just an asset list