[Grace Themes]

Hi Tina,

The size of the logo image is fixed.
If you want to use big size logo image you need to define logo image size in functions.php file

Go to Appearance -> Editor -> functions.php
at line no. 40 you will find the below code, just change the logo image height and width that you want to use

add_theme_support( 'custom-logo', array(
        'height'      => 100,
	'width'       => 100,
	'flex-height' => true,
) );

Regards
Grace Themes