The default image upload file size limit is set to 5 MB (~5 million bytes) on our storefronts. In order to be able to upload bigger file sizes, store administrators should change the default value to their desired need.
To apply changes to the size limit follow these steps:
Select the storefront you wish to increase it's upload limit, then Configuration > Settings > Media Album Settings.
You can also use online converter tools such WhatsaByte to get the right value.