Boxy Bag Base Calculator | Emi B Designs
Emi B Designs · The Bag Making Lab

Boxy Bag Base Calculator

Pop in your finished bag size and we'll work out your fabric cut — then tell you exactly which Boxy Bag Tool to grab.

1 Your finished bag size

All in inches — the size you want the bag to be once it's sewn and standing up.

2 Your cut list

Cut four pieces this size — 2 outer and 2 lining.

Fabric Width
in
Fabric Height (cut ×4)
in
–"
Cut-out square at each bottom cornerCut this square from both bottom corners of each piece (four in total) to box your base.

The tool for the job

Approx. finished capacity: litres (minimum estimate — real bags hold a little more)

How to use your cut-out squares
  1. ×4 1Cut four pieces to the Fabric Width × Fabric Height above — 2 outer and 2 lining.
  2. 2Line your Boxy Bag Tool's square up with the side and bottom edge at each bottom corner, trace, and cut the square away — both bottom corners on all four pieces.
  3. 3Sew your two outer pieces right sides together down the sides and along the bottom, leaving the cut-out corners open — then do the same with your two lining pieces.
  4. sew across 4On both the outer and the lining, match each side seam to the bottom seam, pinch flat, and sew straight across to box the base.
  5. 5Nest the lining inside the outer and finish as your pattern directs — boxed base done!

Remember: the cut-out square is half the finished base depth — a 1" square gives a 2" base, a 2.5" square gives a 5" base.