Missing screw can somebody eyeball the proper size?

I've been using this and have recommended it to several other members as well. Although not the cheapest solution ($25), its an incredibly handy tool to have around! I usually use this to find the size I need then run to home depot/lowes/ace hardware to get the proper bolt.
https://www.amazon.com/dp/B003FJW0GK/?tag=fabo03-20