I started with a hoodie sweatshirt. The plan is to use the extra material from the hood to make the collar. I will remove the zipper and replace it with a button. I thought about how to sew buttons on the sleeve and move the pockets so that they are slots and more professional, but I like the way this looks. I use several coats and hoodies, just pretend all the hoodies are the same one and all the coats are the same. i did it because i didnt want to cut up the nice hoodie until i was sure it would work.

Step 1: Background

I have been looking for templates and sewing patterns to make a sport coat or blazer for a few months with no success. I was curious how complicated it really is to make the coat and because there are no resources for sports coats I'll post my results here. I chose to make the collar a different material than the coat so it shows up better in pictures.

Step 2: Research

Before starting any project, save time by doing research. Since I couldn’t find any instructions on how to make a coat, here are a few example pictures. From this angle, they all look about the same but when the collar is folded out it is easier to see the shape.

Step 3: Make a Template

Fold out the collar and examine the outline.
Compare how it fits to the sweatshirt by placing above the sweatshirt on the hanger.
Make a template of the collar so it can be compared to the extra hood material and the hoodie. There should be plenty of material. I compared half the collar template to half the hood.
On the overlapping jacket and hoodie picture, the edges line up well so I plan to just fold the sweatshirt back and sew material on the inside of the sweatshirt.
The triangles on the outside of the template will need to be cut out of the hood, then sewn on the inside where the zipper was.

Step 4: Start Cutting

Using a razor, cut out the thread to remove the zipper. Be careful not to cut the fabric.
Cut off the hood an inch above where the collar should be.
Cut two triangles mirroring each other that are larger than the inside part of the template. Use an iron and starch to fold the triangles so that they match the template.

Step 5: Start Sewing

The triangles have a nice folded edge that should be aligned with the folded edge on the side of the sweatshirt.
I outlined the triangles on the sweatshirt so that it is easier to see which side aims inwards.
I aligned the top of the triangle to the seam where the hood was sewn on.
Everything is sewn with two parallel lines so that it stays flat. After the triangles are sewn, the back collar needs to be sewn closed.
Iron and starch the collar so that it has two clean folded edges. Don't forget to put in the notch. sew around the collar and notch (see picture).

Sew the button on and a button hole. If you don't know how to sew the hole, follow this.

Step 6: Finishing Up

Iron and starch the collar and about an inch past so that the folded part will hold the fold.
That is about it. If you feel real motivated, you can add buttons to the sleeves or move the pockets.