Weighted Blanket Yarn Calculator
How much yarn do you need to crochet a weighted blanket? Get exact skein counts and total yardage for 5 lb, 10 lb, 15 lb and custom-weight blankets. Preset for worsted and bulky yarn. Free, no signup.
Calculate your yarn
Preset yarn amounts by blanket weight
The formula: Y = (Wblanket ÷ Wskein) × Lskein
— divide target weight by skein weight, multiply by skein yardage.
| Target weight | Yarn weight | Skein specs | Skeins needed | Total yards |
|---|---|---|---|---|
| 5 lb | Worsted (#4) | 200g / 350yd | 12 skeins | 3,969 yd |
| 10 lb | Worsted (#4) | 200g / 350yd | 23 skeins | 7,936 yd |
| 15 lb | Worsted (#4) | 200g / 350yd | 35 skeins | 11,908 yd |
| 10 lb | Bulky (#5) | 300g / 280yd | 16 skeins | 4,233 yd |
| 15 lb | Bulky (#5) | 300g / 280yd | 23 skeins | 6,350 yd |
| 20 lb | Bulky (#5) | 300g / 280yd | 31 skeins | 8,467 yd |
Skein counts rounded up to the next whole skein. Always buy one extra skein from the same dye lot as a safety margin for gauge differences.
The weighted blanket yarn formula
A crochet weighted blanket reaches its target weight through yarn mass alone — there is no polyfill or glass-bead insert in a fully crocheted blanket. So the question "how much yarn do I need?" is really "how much yarn does it take to weigh 10 lb?"
The formula divides the target blanket weight by the weight of one skein, then multiplies by that skein's yardage:
Ytotal = (Wblanket ÷ Wskein) × Lskein
Where Wblanket is the target blanket weight in grams, Wskein is the weight of one skein in grams, and Lskein is the yards per skein.
Worked example: 10 lb blanket
- 1. Convert 10 lb to grams: 10 × 453.592 = 4,535 g
- 2. Read the ball band: worsted #4, 200 g / 350 yd per skein
- 3. Divide: 4,535 ÷ 200 = 22.68 skeins
- 4. Multiply: 22.68 × 350 = 7,936 yards
- 5. Round up: 23 skeins + 1 extra for safety = buy 24
If you switch to bulky (#5) yarn at 300 g / 280 yd per skein, the same 10 lb blanket needs only 16 skeins (4,233 yards) — fewer skeins, but each stitch is bigger so the blanket finishes faster.
Frequently asked questions
How much yarn do I need to crochet a 10 lb weighted blanket?
A 10 lb (4,535 g) weighted blanket using standard worsted-weight yarn (200 g / 350 yd skeins) needs about 23 skeins or roughly 7,936 yards of yarn. If you use bulky-weight yarn (300 g / 280 yd skeins), the same 10 lb blanket needs about 16 skeins or 4,233 yards. Always round up to a whole skein and buy one extra for safety margin.
How do I calculate yarn for any custom weighted blanket?
Divide your target blanket weight by the weight of one yarn skein, then multiply by the skein's yardage. The formula is Y = (W_blanket ÷ W_skein) × L_skein, where W is weight in grams and L is yards per skein. For example, a 15 lb (6,804 g) blanket with 200 g / 350 yd worsted skeins: (6804 ÷ 200) × 350 = 34 skeins = 11,908 yards.
What weight yarn is best for a crochet weighted blanket?
Bulky (#5) or super bulky (#6) yarn is best for weighted blankets because each stitch packs more mass, so you reach the target weight with fewer stitches and a faster finish. Worsted (#4) works but takes roughly twice as many stitches to hit the same weight. Avoid fine or sport weight — the stitch count becomes impractical for a 10+ lb blanket.
Why does my weighted blanket need so much more yarn than a regular blanket?
Because a weighted blanket reaches its target weight (5–20 lb) through yarn mass alone, not stuffing or fillers. A regular throw blanket of the same size might weigh 2 lb and use 1,500 yards; a 10 lb weighted blanket in the same size uses 5–6 times that yardage. The yarn IS the weight — there is no polyfill shortcut in crochet.