Yarn calculator
Work out how much yarn you need for a blanket or any project, in grams, metres, yards and balls, from a swatch you weigh.
How to use the yarn calculator
- Make a swatch at least 6 × 6 inches in your yarn and the stitch you will use.
- Measure its width and length, and weigh it.
- Enter the size of the finished project. The blanket size chart lists standard sizes.
- Copy the ball weight and length from the ball band.
The calculator scales the swatch weight up to the project area, adds your spare, and turns it into balls and length. Not sure which yarn weight you have? Check the yarn weight chart.
Questions
How much yarn do I need for a blanket?
Weigh a swatch made in your yarn and stitch, then scale it up to the blanket size: that is exactly what this calculator does. It is far more accurate than general estimates, because stitch pattern and tension change yarn use a lot.
Why weigh a swatch?
Your yarn, hook or needle size, stitch pattern and tension all change how much yarn a square inch uses. A weighed swatch captures all of them at once. A kitchen scale that reads to 1 g is fine; a 0.1 g jewellery scale is better for small swatches.
How big should my swatch be?
At least 6 × 6 inches (15 × 15 cm), in the stitch you will use for the project. Wash and dry it the way you will treat the finished piece, then measure and weigh it.
How much spare yarn should I buy?
Add about 10% for seams, edging and weaving in ends, and buy all the balls from one dye lot, because colours vary between lots.
Does it work for crochet and knitting?
Yes. It works for any stitch, including C2C, granny squares, tapestry crochet and colourwork, as long as the swatch uses the same stitch and yarn.