Today I was working with a custom WordPress implementation and we had a situation where in the attachment size was going to be around 50mb.

By default the WordPress  installation allows you to upload files with a maximum size of 8mb.

To override this limit all you need to do is create/open the . htaccess file in your WordPress installation directory and add the following lines to it.

php_value upload_max_filesize 50M
php_value post_max_size 50M
php_value max_execution_time 2000
php_value max_input_time 2000

You can modify the file size according to your preference and set a custom upload size