Fix a large gap in my entry door?

I would check the "door" area of your local building store. They sell rubber flashing etc that I think you could tack on there to help.

Trista - Do you have weather stripping on the door? It' an inexpensive rubber tube like material to bridge the gap between the door and frame. If it's old, it could use replacing. Here's step by step how -> https://www.charlestoncrafted.com/2016/08/30/stripped-first-time-weekend/

at big box diy, in the weatherization area, there are plastic/vynial strips 3 feet long, 2 inches thick. they cut with scissors. they have an adhesive on the back.

ive got similar cracks around my door. the strips are usually used on the bottom of the door as a door sweep, , but I have a few vertical to cover similar gaps like yours. 2 bucks maybe? not terrible expensive. if I can find this post on the I pad, i'll see if it will sync, no it isn't going to sync.. bummer.

Go to you tube they have some videos DIY...or call a handyman....doors are a pain.....

I am a retired carpenter, the bottom of the door jamb is caved "toward the stud wall". The inside casing (the decorative trim) needs to be removed on that side, and it needs to be "shimmed" between the stud and the jamb. They sell wedge material, called shims, at Lowe's and Home Depot, or any lumber yard. They are maybe $2.00 for a package. You may need to drive a finish nail in, 2 inches up from the bottom after you install the shims. you can keep closing the door as you add shims to check the gap. Then you "break off what is sticking out past the jamb, or cut with razor knife, and re-install the casing.