The utility below was inspired by this tutorial. I knew I'd forget the dimensions if I tried to make a tote bag later, so I created this simple tool to generate a custom pattern based on a desired bag size. It'll get you close but you may need to make some adjustments based on your fabric and sewing style.
Show Tanner some love at https://claridgeleather.com/.
Bag Specifications
FINISHED DIMENSIONS
SEAM ALLOWANCE
Common values: 0.25", 0.5", 0.625" (5/8"), 0.75"
ROLL TOP SEAM HEIGHT
Pattern Preview
Unified Pattern Total Size: 24.00" W × 36.00" H
Construction Notes
• Cut ONE unified pattern piece from your material (includes both sides and bottom)
• Seam allowances are included in all pattern dimensions
• Fold along the edges where the bottom section meets the side sections
• Sew the vertical seams on each end to create the bag structure
• Use French seams or flat-felled seams for durability
• Roll top allowance added to side height - fold and stitch to create finished edge