Self-Binding Baby Blanket: Jenny Doan's Easy One-Piece Tutorial

🧵 Outer fabric (border + back) — one square, 36" × 36" for a standard baby blanket. This will wrap around to become the border. Shop fabric by the yard here.

🎀 Inner fabric (blanket center) — one square, 30" × 30". This is the front of your blanket. Choose something soft! Shop quilt fabric here.

✂️ Rotary cutter, ruler & cutting mat — you'll need a square ruler with a 45-degree line. Shop quilting rotary cutters.

🪡 Sewing machine — any basic machine will work for this project

📌 Pins or clips — to hold layers in place while sewing. Shop sewing pins & clips.

🔥 Iron and ironing board — for pressing seams and the finished border

Step 1: Cut Your Two Squares

Start with your two pieces of fabric. For a standard baby blanket, cut your inner square to 30" × 30" and your outer square to 36" × 36". The outer square is 6 inches bigger because it will fold up to create a 3-inch border all the way around.

Make sure both squares are truly square — this matters for getting those corners to match up perfectly later on.

Step 2: Create the 45-Degree Corners

This is where the magic happens! Take your outer square (the larger one) and grab a square ruler that has a 45-degree line on it. At each corner, you're going to draw a diagonal line.

Here's how: Line up the 45-degree line on your ruler with the edge of the fabric. Measure in 3¼ inches from the corner (the extra ¼" is seam allowance) and draw your stitch line along that 45-degree angle. Repeat on all four corners. Stitch along the lines, then trim with a quarer-inch seam.

Now take those cut corners and fold them right sides together, matching up the diagonal edges. Each corner will fold into a little triangle. Stitch straight across each folded corner with a ¼" seam allowance.

Be sure to backstitch at both ends — these seams take a lot of use when the blanket is being washed and loved on, so you want them secure. Do this on all four corners.

Step 4: Turn the Corners Right Side Out

Once all four corners are sewn, you'll have little triangular pockets at each corner. Now for the satisfying part — flip each corner right side out!

Put your fingers inside the pocket and push the corner out with your thumb. You want a nice, crisp point. Use a point turner or chopstick if needed to get the corners sharp.

When all four corners are flipped, you'll see your blanket taking shape — a beautiful border frame with mitered corners, all created from that single piece of fabric.

Step 5: Insert the Inner Square

Lay your outer piece flat with the right side facing down and all four borders folded inward. Now take your inner square (the 30" piece) and simply slide it inside the border frame, centering it so the border is even on all four sides.

Smooth everything out so it lays nice and flat. The inner square should tuck neatly under the folded border edges. Pin or clip along all four sides to hold everything in place before sewing.

The blanket comes together beautifully once you turn it rightside out!

Step 6: Topstitch the Border

Head back to your sewing machine and topstitch along the inner edge of the border, securing the border to the inner fabric. Sew about ⅛" from the folded edge of the border, all the way around the blanket.

This stitching serves double duty — it holds the blanket together and adds a decorative detail. Use a thread color that complements your fabric, or use a contrasting color for a fun pop!

Step 7: Press and Admire!

Give your finished blanket a good press with your iron and you're done! Those mitered corners should be crisp and clean, the border should lay perfectly flat, and you should be feeling pretty proud of yourself right about now.

The whole project takes about 30 minutes from start to finish — meaning you could easily make several in an afternoon for baby shower gifts. They're so quick and satisfying that you might find yourself making one for every baby you know!