How to change the size of menu item icon in NavigationView?

Question

I have the following menu item:

Answer 1

The main thing that decide the icon's size is the dimension:navigation_icon_size, have a look at the NavigationMenuItemView class:

 public NavigationMenuItemView(Context context, AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);
    this.mIconSize = context.getResources().getDimensionPixelSize(dimen.navigation_icon_size);
}

so, we can just overide the property in our dimens file.

For example:

48dp

add that code in the dimens file, and you can find it's size changed.

Before:

After: