Yardage estimator
How much yarn do I need?
Pick a project and size, then estimate the yarn from its weight category or, more accurately, from a swatch you have weighed. Results in metres, yards, balls and grams.
Yarn to buy
719–1,039 mmetres of yarn
786–1,137 ydyards of yarn
11 ballsof 100 m / 50 g (8 at the low end)
- By weight that is about 360–520 g.
- Fabric area: about 0.83 m² (8.9 sq ft).
- At 4 Medium (16–20 sts per 4 in, CYC), a 10 cm square of stocking stitch takes about 7.9–10.4 m of yarn.
- The range adds 10–20% for seams, edgings, your swatch and weaving in ends. Ribbing, garter, cables and colourwork use more than stocking stitch: weigh a swatch for those.
- Buy every ball from the same dye lot (the lot number on the band): colours can shift between lots, and the shop may not have your lot later.
Swapping to a different yarn?
You need9 balls (720 m / 787 yd)
The pattern uses 720 m (787 yd) in all: 9 balls of your 85 m yarn. Compare length, not weight: different fibres weigh differently for the same length.
How the estimate works
Choose what you are making and a size. Each size fills in typical finished measurements; change any of them to match your pattern's schematic, which is the most accurate starting point.
Yarn weight takes the Craft Yarn Council stitch gauge range for that weight, or your own gauge, and works out the yarn in a square of stocking stitch. Textile research on plain knitting (Munden, 1959) found that relaxed knitted loops keep a nearly constant shape, so the yarn in each square centimetre is about 5 to 5.3 times the number of stitches per centimetre, in centimetres. The calculator multiplies that by the project's area and adds 10–20% for seams, edgings, the swatch and weaving in ends.
My swatch is more accurate and works for any stitch, crochet included. Make a swatch at least 15 cm square in the project's stitch, wash and dry it, measure it, then weigh it on a kitchen scale or unravel it and measure the yarn. The calculator scales it up to the project's area.
Ball band is the length and weight of one ball or skein, so the answer can be given in balls and grams.
Worked example
A woman's medium sweater (104 cm chest, 58 cm long, 43 cm sleeves) has about 0.83 m² of fabric. In worsted-weight yarn that comes to roughly 720–1,040 m, or 8 to 11 balls of 100 m. Round up, and buy every ball from one dye lot.
Sources
- Craft Yarn Council, Standard Yarn Weight System: the stocking stitch gauge range for each weight.
- Craft Yarn Council body measurements: the woman size chart, man size chart, child and youth size charts, baby size chart, head circumference chart and foot size chart, used for the size presets (with the ease and lengths stated under the fields).
- Munden, D. L. (1959). The geometry and dimensional properties of plain-knit fabrics. Journal of the Textile Institute Transactions 50, T448–T471: loop-shape constants of about 5.0 (dry relaxed) and 5.3 (wet relaxed) for courses per loop length in plain-knit wool.
Questions about yarn amounts
Why is the answer a range and not one number?
Knitters with the same yarn get different gauges, and every pattern has its own edgings and shaping. The low end uses the loosest gauge for the yarn weight plus 10%, the high end the tightest gauge plus 20%. Your own swatch narrows the range a lot.
Why buy all the yarn from one dye lot?
Each batch of dyed yarn gets a lot number on the band, and colours can differ slightly between batches. The difference often shows as a line where you join a new ball. Buy everything from one lot, and if you are near the top of the range, buy the extra ball now rather than hunting for your lot later.
Does this work for crochet?
Use the My swatch method. The yarn weight method is based on knitted stocking stitch, and crochet stitches pack yarn differently from knitting and from each other. Weighing a crochet swatch measures your own stitches, so it holds for any stitch.
Can I swap yarns by weight in grams?
Not reliably. Two 50 g balls of the same thickness can hold very different lengths: cotton and linen are heavier than wool for the same length, and airy brushed yarns are lighter. Compare metres or yards, as the substitution helper above does.
How accurate is the swatch method?
About as accurate as your measuring. Kitchen scales usually read to the nearest gram, so a 5 g swatch can be off by 10%. A bigger swatch, or several weighed together, gives a firmer number. Measure the swatch after washing, in the same state as the finished piece.