How to use the tote bag cutting dimensions calculator
- Enter the finished width, finished height and finished depth of the bag, in one length unit such as inches. Use 0 for the depth if you do not want boxed corners.
- Enter the seam allowance and the extra at the top edge, which is added to each panel for the seam or fold that joins the outer bag to the lining.
- Enter the strap width and length. Under Advanced options choose how the strap is made and how much extra length goes into the bag at each end.
- Read the cutting list. Sizes are rounded to the nearest sixteenth of a unit.
Formula
panel width = finished width + 2 x seam allowance
corner square = depth / 2 + seam allowance
panel height = finished height + corner square + top extra
strap folded in four: cut width = 4 x finished width sewn tube: cut width = 2 x finished width + 2 x seam allowance
When the corner is opened and flattened, the bottom seam and the side seam meet in the middle of a straight edge as long as two corner squares. The stitching line across it runs between the two places where those seams meet, each one corner square minus one seam allowance from the middle, so the finished depth is 2 x (corner square - seam allowance).
A lined tote 14 wide, 15 high and 4 deep
With a 1/2 inch seam allowance and 1/2 inch extra at the top, each outer panel is 15 wide and 18 high, because the corner square is 4 / 2 + 0.5 = 2 1/2 and 15 + 2.5 + 0.5 = 18. The lining uses the same sizes. Cut a 2 1/2 inch square from each bottom corner of all four panels (8 squares in all). The depth check gives 2 x (2.5 - 0.5) = 4 and the height check gives 18 - 0.5 - 2.5 = 15.
A 1 1/2 inch wide strap, folded in four, is cut 6 inches wide, and a 24 inch strap with 1 inch sewn into the bag at each end is cut 26 inches long. With a sewn tube instead, the cut width is 2 x 1.5 + 2 x 0.5 = 4 inches. A 10 1/2 inch wide bag with a 3/8 inch seam gives a panel 11 1/4 wide.
Why the corner square is half the depth plus a seam allowance
Boxing the corners gives a bag a flat bottom. You cut a square from each bottom corner of the sewn panels, pull the cut edges apart so the side seam lines up with the bottom seam, and stitch straight across. The stitching sits one seam allowance in from the cut edge, so the finished depth is a little less than twice the square. Adding one seam allowance to half the depth corrects for that.
The boxing also uses up height: the bag ends up about the depth of the square shorter than the panel, which is why the height includes the corner square.
Making the pattern work for your fabric
These are sizes for a plain two-panel bag. Thick fabric takes up more length at each fold, interfacing adds body, and pockets or a zipper need their own pieces. Make a test bag from scrap fabric before cutting good cloth. To work out how much fabric to buy, see the Fabric Yardage Calculator, and for related cut sizes the Pillow Cover Size Calculator and the Yarn Yardage Calculator.
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For planting dates, sprinklers and water changes, try the Succession Planting Schedule Generator, Sprinkler Layout and Spacing Calculator and Aquarium Water Change Calculator.
Assumptions and limits
- The bag is made from two panels joined at the sides and bottom, with an outer bag and a lining of the same size.
- All sizes use one length unit and include seam allowances.
- Fabric stretch, thickness and pattern matching are ignored.
- Straps are cut as two identical pieces; pockets, zippers and interfacing are not listed.
- The example sizes are an illustration. Replace them with your own.
Frequently asked questions
Do I cut the lining the same size?
This page uses the same size for the lining so the two bags fit. Many makers cut the lining a little shorter to reduce bulk at the top. Subtract that from the height if you want it.
What if I do not want boxed corners?
Enter 0 for the depth. The panels then have a bottom seam only, and the height is the finished height plus a seam allowance and the top extra.
Why is each strap longer than its finished length?
The ends are stitched into the bag, so the cut length adds the extra you enter at each end. One inch at each end is an example only.
Are fractions of an inch exact?
They are rounded to the nearest sixteenth. A size that is not close to a sixteenth, such as one in centimeters, is shown as a decimal with up to five digits instead.