
I spotted some painted arches online and I really wanted to do a DIY painted arch on the wall above our Dutch door that leads into the kitchen. Our house is majorly lacking in character so I am adding some any chance I get. The only arch tutorials I found online were based on your outer door trim to outer door trim width being the actual radius of the circle. They have you measure half of the width of your outer door trim to outer door trim, cut a string that length, and then trace your arch with a pencil attached to the string from the center. Crazy simple, however my ceilings are only 8′ high and I didn’t have enough room for that so I figured out another way to do this. There’s a little bit of geometry involved but it ended up being pretty simple.
Below are the supplies I used to create this DIY painted arch. Let me show you how I did it!
Supplies
- Cardboard (or paper or plywood for the template)
- Measuring tape
- Arc Calculator (I used ArcCalc for iPhone. It was free and simple.)
- Pencil
- String
- Scissors
- Paint brush
- Paint
- Painters tape
Step 1: Measure
You will only need to take two measurements. 1) Measure the width of your door from outer trim to outer trim. Mine ended up being 41.375″. 2) Measure how high you want your arch to be. I decided to do 10″.

Step 2: Calculate the apothem
Enter these measurements into an arc calculator to find the apothem. I found an app for free called ArcCalc on my iPhone. I’m sure there are others but this was the first one I found and it was free! I entered in my my width and my height and the calculator gave me the apothem to complete the project.

Step 3: Create your template
If you have a door you can skip this step. I didn’t have anything below my arch to attach string to so I needed to make a template to trace. If I had been doing this above a door I would have taped my string to it and traced my arch directly onto the wall.

I had some boxes laying around so I ended up taping two together so that it was wide and tall enough for this template. You could tape together pieces of paper or use plywood. I marked out the width and found the midpoint. From the midpoint I went up how high I wanted my arch. For me it was 10″. Then, I went down from the midpoint and marked the apothem length. I got this from the calculator. I took a piece of string I had laying around and cut that to be my height (10″) plus the apothem (1.3665′) and a little room to tie a pencil to it. I taped my string to the bottom of the apothem and I tied the top of the string to a pencil. I had my husband hold down the tape and I tightly pulled on that string so that it touched the top of the height and made my arch making sure that I hit both of my endpoints. I didn’t have a large ruler so I just used painters tape to create a line from each endpoint. Then I cut out the cardboard template. Trust me, my template was not a perfectly cut edge. It was a little jagged because I didn’t use super sharp scissors but it didn’t end up mattering.
Step 4: Trace Template on Wall
I held it up above my doorway to see if it was in fact correct. Mine did line up with the width of my outer door trim so I taped the cardboard up with a few pieces of painters tape and I traced around it with a pencil.

Step 5: Paint
Once I had it traced I took the cardboard off and painted the arch. I did not use painters tape as it would’ve taken too long since it’s not a straight line. I decided to just freehand it. I made sure that when I was doing the edge I pushed my paintbrush all the way down so it was flushed out and I just carefully went around the edge. I painted the door trim green as well. I definitely used painters tape for the trim. It’s well worth the time taping it up especially when painting such a dark color near white.
Tip: I like to put my paintbrush in a plastic bag and leave it in the fridge for second or third coats (until I am all done painting). I don’t like rinsing my brush after each coat. I just rinse it at the end. You can leave the paintbrush in the fridge for days.

This paint color is Backwoods by Benjamin Moore in a semi gloss finish. I have little kids so having easy to wipe surfaces is necessary for me and that is the paint I already had laying around from another project. We do not have Benjamin Moore near us so we just went to Home Depot and had them make this color with Behr paint.
This Dutch door is the DIY we did just after this DIY painted arch. If you want to see how we did it you can check out that DIY here.
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