What You'll Make and What You Need

A sling bag is a rectangular fabric pouch with a long strap that crosses your body, leaving your hands free. This guide walks you through sewing one from two pieces of fabric, a strap, and basic supplies. The finished bag measures roughly 10 inches wide by 12 inches tall—large enough for a phone, wallet, and keys, but small enough to carry comfortably.

Gather these materials before you start: two pieces of cotton fabric cut to 11 inches by 13 inches (the extra half-inch is for seam allowance), one piece of fabric for the strap measuring 4 inches by 40 inches, thread that matches your fabric, a needle or sewing machine, scissors, pins, and a ruler or measuring tape. A seam ripper is useful if you make mistakes, but not essential.

If you're sewing by hand, expect this project to take three to four hours spread over a few days. Machine sewing cuts that time to about one hour. Either method produces a sturdy, functional bag.

Key Takeaways

  • Cut your main fabric pieces to 11 by 13 inches and your strap fabric to 4 by 40 inches before you begin pinning or sewing.
  • Sew the two main pieces together with the right sides facing inward, leaving a 3-inch opening at the bottom for turning the bag right-side out.
  • Fold the strap fabric in half lengthwise, sew along the long edge, then turn it right-side out and press flat to create a finished strap.
  • Attach the strap ends to the inside seams of the bag before closing the opening, so the stitches are hidden inside the finished bag.
  • Hand-stitch the final opening closed using a ladder stitch, which creates an invisible seam from the outside.

Cutting and Preparing Your Fabric

Lay your two main fabric pieces on a flat surface and measure them carefully. Each piece should be exactly 11 inches wide and 13 inches tall. Use a ruler and a fabric pencil or chalk to mark the cutting lines, then cut slowly and straight. Uneven edges make the seams harder to align later.

For the strap, cut one piece of fabric 4 inches wide and 40 inches long. This length wraps around your body comfortably; if you're taller or prefer a longer strap, add a few extra inches. Cut the strap on the straight grain of the fabric (parallel to the selvage edge) so it doesn't stretch out of shape as you wear the bag.

Once cut, lay the two main pieces with their right sides (the pretty, printed side) facing each other. This is called "right sides together." Pin them along three edges, leaving the bottom edge unpinned for now. Place pins every 2 to 3 inches, pushing them straight through both layers so they hold the fabric flat and aligned.

Sewing the Main Bag Body

If you're using a sewing machine, set it to a straight stitch with a stitch length of 2.5 millimeters. Thread the machine, place the pinned fabric under the presser foot, and sew along the right side, starting at one top corner. Sew down the right edge, across the bottom, and up the left edge, stopping about 3 inches before you reach the top. Backstitch (sew in reverse) for a few stitches at the start and end to lock the thread.

If you're sewing by hand, thread your needle and tie a knot at the end. Use a running stitch: push the needle through both layers, then back out about a quarter-inch forward, then back in again. Keep your stitches small and even, about the same size as a grain of rice. Sew the same three sides, leaving the 3-inch opening at the bottom.

The 3-inch opening is where you'll turn the bag right-side out later. Leave it unpinned and unsewn. Once you've finished sewing the three sides, remove the pins and trim the corners diagonally, cutting about a quarter-inch from each corner. This reduces bulk when you turn the bag right-side out and makes the corners look sharper.

Making and Attaching the Strap

Fold your 4-by-40-inch strap fabric in half lengthwise, with right sides together. Pin along the long edge. Sew from one end to the other, using a quarter-inch seam allowance (the distance between the edge of the fabric and your stitching line). Leave both short ends open.

Now turn the strap right-side out. This is the trickiest part. Tie a knot in a length of thread and push the needle through the fabric at one end of the strap. Pull the thread to create a small loop, then use a safety pin or bodkin (a blunt metal tool) to grab that loop and pull it through the tube of fabric. The strap will gradually flip inside-out as you pull. Once it's turned, press it flat with an iron on medium heat, centering the seam on one side.

Before you close the main bag, attach the strap. Push the two short ends of the strap into the 3-inch opening at the bottom of the bag, positioning them so they're sandwiched between the two layers of the main fabric. The strap ends should sit about 2 inches in from each side seam. Pin them in place, making sure the strap isn't twisted.

Closing the Bag and Finishing the Seams

Fold the raw edges of the 3-inch opening inward by half an inch and pin them closed. The strap ends are now trapped inside, hidden between the two layers. Sew this opening closed using a ladder stitch, also called an invisible stitch. This stitch is worked from the outside and creates a seam that's nearly invisible.

To ladder stitch by hand: bring your needle out through the fold of fabric on one side of the opening. Slide the needle horizontally inside the fold for about a quarter-inch, then bring it back out. Cross over to the opposite side and repeat, sliding the needle inside the fold on that side. As you work, pull the thread gently every few stitches to close the opening. The two sides of fabric will fold together, and the thread will run hidden inside the fold.

If you're using a machine, use a ladder stitch setting if your machine has one, or a narrow zigzag stitch set to a very short length. Sew slowly and carefully along the opening. Once the opening is closed, the strap ends are permanently anchored inside the bag, and the seam is invisible from the outside.

Pressing and Final Details

Press the entire bag with an iron on a medium setting. Lay it flat and press the main body, then press the strap. This sets the seams and gives the bag a finished, professional look. If you used hand stitching, pressing also helps the stitches settle into the fabric.

Check all the seams by running your fingers along them. If you feel any loose threads, trim them with scissors. If a seam feels weak or has a gap, you can reinforce it by sewing over it again, either by hand or machine. This is especially important where the strap attaches, since that's where the bag bears the most weight.

Try on your finished bag. Adjust the strap length if needed—it should sit comfortably across your body without digging into your shoulder. If the strap is too long, you can shorten it by removing the ladder stitches at the bottom opening, pulling out the strap, trimming it, and re-sewing it in place.

Common Mistakes and How to Avoid Them

The most common mistake is sewing the strap ends to the outside of the bag instead of sandwiching them inside. This creates visible, bulky seams and weakens the attachment. Always insert the strap ends into the 3-inch opening before you close it, so they're hidden between the two layers.

Another frequent problem is uneven seams. If your stitches are too large or inconsistent, the seams won't hold up to regular use. Aim for stitches about a quarter-inch long, and keep them as uniform as possible. If you're using a machine, practice on scrap fabric first to get a feel for the speed and tension.

Twisted or wrinkled straps happen when you don't press them flat after turning them right-side out. Always press the strap before attaching it. If the strap twists during wear, you can remove it and re-press it, or straightforward adjust it by hand each time you wear the bag.

Corners that look lumpy or uneven usually result from not trimming the seam allowance at the corners. Always cut the diagonal corners before turning the bag right-side out. This removes excess fabric and lets the corners fold neatly.

Frequently Asked Questions

Can I make a sling bag without a sewing machine?

Yes. Hand sewing takes longer—three to four hours instead of one—but produces the same sturdy result. Use a running stitch for the main seams and a ladder stitch for the final opening. Your stitches just need to be small and even, about a quarter-inch long.

What fabric works best for a sling bag?

Cotton, linen, and canvas are all good choices. Avoid stretchy fabrics like jersey or spandex, which won't hold their shape. If you want a sturdier bag, use canvas or quilted cotton. For a lighter bag, regular cotton or linen works fine.

How do I make the strap longer or shorter?

Adjust the length of the strap fabric before you sew it. The 40-inch length is a starting point; add or subtract inches depending on your height and preference. A longer strap (45 to 50 inches) works better for taller people or if you like the bag to sit lower on your hip.

What if my strap is twisted inside the tube?

Use a safety pin or bodkin to pull it through more slowly, checking every few inches to make sure it's not twisting. If it does twist, push it back inside and start again. Once it's turned right-side out, press it when ready with an iron to set the shape.

Can I add pockets or a lining to the inside?

Yes. Before you sew the two main pieces together, sew a pocket piece to the inside of one of the main fabric pieces. A straightforward rectangular pocket sewn on three sides works well. You can also add a fabric lining by cutting two extra pieces the same size as the main pieces, sewing them together, and inserting them inside the bag before closing the final opening.