How do I display the file size and format of attachments on a node templates? In the node template I output the attached files (multiupload file field). Need to output the size and format of each file. I do it like this:
{% for file in node.field_news_files %}Size {{ file.entity.filesize.value }} in {{ file.entity.filemime.value }} format{% endfor %}

I get this result: Size 2227507 in APPLICATION/PDF format
The goal is to get this result: Size 2MB in PDF format
Can I output the data as I need in the node template or do I need to redefine it file-link.html.twig?
There's a module which provides a Twig filter for that: Format Bytes

In twig when you get the value of a file, the size is in simple bytes and if you're intending to show it to your end-user, it's not user-friendly, this simple Twig filter helps with that and renders the file size in it's respected: 'B', 'KB', 'MB', 'GB', 'TB'

Example usage:
{{ node.field_attachment.entity.field_file.entity.filesize.value | format_bytes }}

The alternative would be to do the same formatting that module does in your own preprocess function for the template.