How to Plan a Granny Square Blanket
The math is simple: divide the blanket dimensions by the square size to get the number of columns and rows. Multiply columns by rows to get the total number of squares. Then estimate yarn per square based on the square area and your yarn weight.
Account for a border by subtracting the border width from each side before calculating squares. A 2-inch border on a 50 x 60 throw means the squares fill a 46 x 56 area.
Granny Square Sizes Reference
| Square Size | Yarn Per Square (worsted) | Rounds | Best For |
|---|---|---|---|
| 6 inches | ~20 yards | 4-5 rounds | Quick projects, multicolor designs |
| 8 inches | ~35 yards | 5-7 rounds | Standard blankets, versatile size |
| 10 inches | ~55 yards | 7-9 rounds | Fewer squares to join, faster assembly |
| 12 inches | ~79 yards | 9-11 rounds | Large projects, pillow covers, afghans |
Squares Needed by Blanket Size
| Blanket | Size | 6" squares | 8" squares | 12" squares |
|---|---|---|---|---|
| Baby | 30" x 36" | 30 | 20 | 9 |
| Throw | 50" x 60" | 80 | 48 | 20 |
| Twin | 66" x 90" | 165 | 99 | 48 |
| Queen | 90" x 100" | 255 | 143 | 72 |
FAQ
How much extra yarn should I buy for joining squares?
Joining adds 10-15% to total yarn usage. Whip stitch uses the least yarn, while join-as-you-go and flat braid joins use more. Budget an extra yard per square for joining and weaving in ends.
Can I mix different square sizes?
It's possible but tricky. Squares must fit together evenly, so you'd need to combine sizes that work mathematically (e.g., one 12-inch square equals four 6-inch squares). Plan your layout on graph paper first.
What yarn weight is best for granny squares?
Worsted weight (#4) is the most popular choice — it works up quickly and is widely available. DK weight gives a lighter blanket with more drape. Bulky yarn makes a thick, warm blanket but uses more yarn and makes larger squares.
Related Tools
- Yarn Yardage Calculator — estimate yarn for any project
- Crochet Blanket Calculator — plan solid-stitch blankets
- Crochet Chain Calculator — foundation chain length