Blanket Yarn Estimator
Yarn for a blanket: standard sizes or your own, a border and stripes – the skeins to buy for each colour.
Blanket yarn estimator by Envelo BlanketSum: the stitches to cast on, the rows to knit and how many skeins to buy for each colour – from your own swatch, for a standard size or your own, with a border and a little spare.
A striped blanket is where yarn maths goes wrong: one colour runs out, another fills the stash. BlanketSum works it out from a small swatch you knit and weigh, so it fits your yarn, your hook or needles and your stitch – and it rounds every colour up to whole skeins on its own.
Try it here
A live demo with a made-up example. Nothing you type here is saved or sent anywhere.
What it does
What you can do
- Pick a standard size – baby, lap, throw, twin, queen, king – or enter your own, in cm or inches, with a border on each side
- Enter your gauge – stitches and rows over 10 cm (4 in), fractions too – and your swatch size and weight
- Enter the grams and length of a skein from the yarn label and how much spare you want
- Add up to 12 colours with their share of the blanket; the border counts as its own colour
- Get the stitches to cast on, the rows, the finished size, the yarn in grams and metres or yards, and the skeins to buy for each colour
- A pattern card with the stripes and all the numbers: download as SVG or print on A4 or US Letter
- The skeins for each colour as a CSV table, backup and restore
Example inside
A made-up striped throw, 127 × 152 cm, in Aran wool at 16 stitches and 20 rows over 10 cm, with a 5 cm border: cream 50 %, sage 30 %, rust 20 %. The body takes 1887.5 g and the border 282.6 g; with 10 % spare that is 11 + 7 + 5 skeins of 100 g and 4 for the border – 27 in all. Cast on 203, knit 304 rows; finished size 137 × 162 cm.
How it works
- Download the ZIP and START-HERE.pdf from Etsy after checkout.
- Unzip and open Envelo-BlanketSum.html in your web browser. Look at the filled example, then press My numbers.
- Enter your blanket, your swatch, your yarn and your colours. Everything updates as you type and saves in your browser.
What you receive
- START-HERE.pdf (0.12 MB)
- Envelo-BlanketSum-v1.0.zip (1.62 MB)
Inside the ZIP:
- Envelo-BlanketSum.html: the app, opens in your browser by double click and works offline, 11 languages, cm or inches
- examples/: the filled example as a backup file, its pattern card as SVG and its skeins for each colour as CSV
- START-HERE/: the guide in 11 languages
- LICENSES.txt and WHAT_YOU_GET.txt
Good to know
- This is a digital download. Nothing is shipped.
- No subscription and no account. The app runs on your device and uploads nothing.
- BlanketSum works with the numbers you enter. Yarn and stitches differ – knit and weigh a swatch first, and keep the spare.
- Your numbers do not sync between devices; move them with the backup file.
- For your own use. Please don't resell or share the files.
- The app, its logo, the texts and the translations were made as code with the help of an AI coding assistant. No AI image generators were used.
A closer look
Buy it on Etsy and download the files straight away.