Plan your yarn with confidence
Estimate how many yards, metres, and skeins you need using your own measured swatch.
Start calculatingMeasured, not guessed
Plan from the yarn you already own
Choose I know how much yarn I have when your yarn supply is fixed. A measured swatch lets SkeinWise reflect your stitch, hook, yarn, and tension instead of relying on a generic chart.
The calculator removes your chosen reserve first, leaving a visible allowance for joining, small tension differences, or finishing work.
Maximum likely area = Usable yarn ÷ measured yarn density. Your swatch supplies the density.
The available area is divided into width and length using your selected proportion. Dimensions are rounded down so the displayed maximum is not larger than the estimate.
A 4 × 4 inch swatch uses 12 yd, and a 10% reserve leaves 1,800 yd for the blanket body. With the 5:6 throw proportion, the likely whole-inch result is about 44 × 53 inches. Conservative and optimistic dimensions make normal crochet variation visible.
| Shape | Proportion | Reference |
|---|---|---|
| Square | 1:1 | No fixed reference |
| Baby blanket | 4:5 | 36 × 45 in |
| Throw blanket | 5:6 | 50 × 60 in |
| Twin blanket | 2:3 | 60 × 90 in |
These are planning proportions, not rules. Use Custom proportion for another shape. Borders, seams, fringe, motifs, and construction not represented by the swatch need additional yarn.
Crochet planning guides
01
Make a sample that reflects the yarn, hook, stitch, and tension you will use in the finished blanket.
02
Understand area scaling, uncertainty, planning buffer, and why generic yardage charts can miss.
03
Follow complete imperial and metric calculations from swatch measurements to whole skeins.
Better input, better estimate
Use the same yarn, hook size, stitch pattern, and working tension you plan to use for the blanket. A generic gauge square made with a different stitch does not represent the same fabric density.
Use a large, regular rectangular swatch. Lay it flat without stretching and measure its full fabric width and height, including the worked edges. If the edges are badly distorted, make a more regular sample. Do not combine an inner-area measurement with whole-swatch yarn use.
Measure the yarn used by that same whole swatch, excluding loose tails: either unravel it and measure the worked yarn length, or weigh the fully dry fabric on a tared scale. Weight mode also needs the length and weight printed on the yarn label. The selected ±5%, ±10%, or ±20% range is a planning assumption, not a tested accuracy guarantee.
Real calculations
A 4 × 4 inch swatch uses 12 yards. A 50 × 60 inch throw has 187.5 times the area, so the likely estimate is 2,250 yards. Normal ±10% uncertainty produces a 2,025–2,475 yard range. A separate 10% purchase buffer brings the planning basis to 2,722.5 yards, or 13 skeins of 220 yards.
A 10 × 10 cm swatch weighs 8 g and the target is 100 × 100 cm. The area ratio is 100, so the likely estimate is 800 g. With close-match uncertainty of ±5%, the range is 760–840 g. A 10% buffer means planning for 924 g, rounded to 10 skeins of 100 g.
Select rough match (±20%) when your swatch is small, your tension changed while making it, or the blanket includes construction you did not sample. A wider range is more honest than presenting a precise number from uncertain input.
Transparent by design
Area ratio = blanket area ÷ swatch area
Likely yarn = swatch yarn × area ratio
Range = likely yarn ± selected uncertainty
Purchase basis = high estimate × (1 + planning buffer)
The calculator keeps full precision internally. It rounds only the displayed yarn values, then rounds the final purchase quantity up to a whole skein. Uncertainty and planning buffer are never hidden inside one unexplained percentage.
Read the full Methodology & Validation notes for what the automated tests verify and what still needs real-project evidence.
What changes the result
Area scaling works best when your sample truly represents the blanket body. Borders, joins, motifs, fringe, tassels, colour changes, frogging, yarn-lot variation, and a change in tension can all move actual use outside the estimate. Use the result to plan—not as a guarantee that a particular number of skeins will finish every construction.
Private by architecture
The calculator runs in this browser tab. It does not upload your swatch, measurements, or result to a server.
Common questions
Crochet is physical work, so two blankets with the same dimensions may not use identical yarn. A range makes uncertainty visible and separates it from the extra amount you deliberately choose to buy.
Only when the measured swatch represents that border construction. Otherwise estimate the blanket body here and plan the border separately.
Consider dye-lot availability, return policies, and how uncertain your sample is. The planning buffer lets you express that choice instead of adding an invisible extra skein.
Yes. Weigh your swatch and available yarn in grams, then enter the length and weight printed on the yarn label if you also want an equivalent length.
The area-scaling principle is similar, but this version is written and tested for crochet planning. It does not yet include knitting-specific guidance.