Triangular Shawl Calculator

Here’s a little way to calculate the maximum number of rows you can work on a shawl (top down shawls only). You need to have knitted at least 20% of your yarn to do get an accurate answer, though it will return a result with more than 10% yarn used.

Triangular shawl
This calculation will work for any shawl pattern that starts at the top and has a consistent number of increases in each row. (ie. 4increases on every right side row and 2 sts on every wrong side row, or 4increases every other row.)
(Examples of this type of shawl are: ‘Swallowtail’, ‘Ishbel’, ‘Aeolian’, ‘Kiri’, ‘Traveling Woman’, My ‘Dew Drops’ & ‘Danish Ripple’ Shawls)
(I know these shawls have slightly different shapes, but trust me the maths works for all of them.)

You need to know:

Number of Constant stitches in each row: (eg. Swallowtail:5, Ishbel:7, Aeolian:5or7.) (usually edge stitches on each side + centre stitch) (If you don’t know this don’t worry too much as it doesn’t make a huge difference to the result.)

Total yarn weight: (This is how much yarn you have available for the project, in grams is best.)

Used yarn weight so far: (This is the total weight of yarn minus what you have left un-knitted.)

Rows worked so far: (with many shawl you can count the number of holes running up the middle next to the centre st and x2).

RESULT
Maximum Number of Rows:

This result is the number of rows you can work with the yarn you have available, it allows you 3rows worth of yarn to cast off which is sufficient for a very stretchy bind off.
If you pattern has a lot of increases in the final few rows, ie lots of yarn over’s for a pointier edge you will need to subtract a few more rows to allow for that.
If your pattern tells you to cast off with the yarn held double you will need to subtract a few more rows to allow for this.

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I hope you find this page useful, I provide it free for everyone, please link to it here.
Contact me through Raverly, or email me if you have any questions.
P.s. Please don’t blame me if the answer doesn’t work out for you, I provide this script working to the best of my knowledge, free to everyone.
(c) Bex Hopkins 2010, please do not attempt to steal this script.
If you would like to know how this is calculated please contact mes.