Guides / 05—08
Estimate edging tape from perimeter
For a rectangle, perimeter starts the tape estimate; joins and allowances still need recording.
Measure the edges being bound
A rectangle bound on all four sides has perimeter twice the sum of length and width. If one edge remains unbound, subtract that edge; this site's tool assumes all four sides are bound. Measure along the installation line appropriate to your technique rather than copying another project's dimensions.
Allow for joining
Tape may need extra length for the starting and ending join, mitred corners or a technique test. Enter the extra length you choose. The arithmetic does not prescribe how to join bias tape, select its width or assess seam strength.
Compare pack lengths
When tape is sold by the roll, divide planned length by length per roll and round up. Verify the pack label and whether joins must avoid certain edges. Try a small corner sample before cutting every length.