How Many Granny Squares for a Blanket: A Planning Guide
Plan your granny square blanket with confidence: measure your blocked square, choose a finished size, calculate rows and columns, and adjust for joining and borders.
Maggie
Blanket calculator
Blanket size calculator for knitting and crochet
Choose the finished width and length, then calculate knitting cast-on stitches or a crochet starting chain and row count at your gauge, adjusted to fit the stitch repeat.
Use inches for the finished blanket dimensions. The calculator uses a 4 in gauge span.
The width you want the finished blanket to be.
The height you want the finished blanket to be.
The border added on each side, outside the blanket body.
From your blocked swatch over 4 in.
Optional. Enter if you want rows as well as stitches.
From the pattern's repeat. Use 1 if unsure.
The extra stitches outside the repeat.
Optional. Use the pattern's row repeat if known.
Your result
Show the math
Cast on 250 stitches for a 50 × 60 in blanket. Use 420 rows to reach 60 in finished height.
| Usable width | 50 in - 2 × 0 in | = 50 in |
|---|---|---|
| Stitch gauge | 20 sts ÷ 4 in | = 5 sts/in |
| Raw stitches | 50 in × 5 sts/in | = 250 sts |
| Rounded cast-on | Round to any stitch count | = 250 sts |
| Body width | 250 sts ÷ 5 sts/in | = 50 in |
| Finished width | 50 in + 2 × 0 in | = 50 in |
| Usable height | 60 in - 2 × 0 in | = 60 in |
| Row gauge | 28 rows ÷ 4 in | = 7 rows/in |
| Raw rows | 60 in × 7 rows/in | = 420 rows |
| Rounded rows | Round to 1n | = 420 rows |
| Finished height | 60 in + 2 × 0 in | = 60 in |
Counts are rounded to the pattern repeat. Ties round up to the larger count.
The general formula
usable_width = target_width - 2 × border_width stitches_per_unit = stitch_gauge ÷ span raw_stitches = usable_width × stitches_per_unit cast_on = round_to_multiple(raw_stitches, multiple, plus) actual_body_width = cast_on ÷ stitches_per_unit actual_finished_width = actual_body_width + 2 × border_width rows_per_unit = row_gauge ÷ span raw_rows = usable_height × rows_per_unit row_count = round_to_multiple(raw_rows, row_repeat, 0) actual_body_height = row_count ÷ rows_per_unit actual_finished_height = actual_body_height + 2 × border_width
What this calculation does not account for
- Border stitch counts, construction, or yarn use. Enter the planned border width so the calculator can size the main body, then work the border using your pattern.
- Crochet turning chains or foundation-chain extras required by a specific stitch pattern.
- Granny-square or motif assemblies. For square-based blankets, use the granny-square calculator instead.
- Lace and openwork tension changes, which can alter the final size after blocking.
Last updated 1 September 2026Found a wrong number? Tell us.
How to use this
- Enter the finished dimensions you want for the whole blanket. If you plan to add a border, enter its width separately so the calculator can size the main body correctly.
- Enter your gauge from a blocked swatch worked in the actual stitch pattern.
- Enter the pattern repeat so the stitch count is valid. Leave it at 1 if the pattern does not specify a multiple. The row repeat is optional.
Choose dimensions, then calculate blanket stitches and rows
Start with the finished width and length from a size chart, pattern, measured bed, or your own plan. Blanket labels such as baby, lap, throw, and bed size are useful starting points rather than fixed standards, so enter the dimensions that fit the intended use.
The calculator subtracts any planned border from those finished dimensions, multiplies the usable body width by your stitch gauge, and adjusts the result to a valid pattern repeat. When you provide row gauge, it uses the usable body length to calculate the matching row count.
One calculator for knitted and crochet blankets
The size math is the same for both crafts: finished dimensions multiplied by blocked gauge. Use the terminology and repeat supplied by your knitting or crochet stitch pattern.
Worked blanket example
A 50-inch blanket at 4 stitches and 5 rows per inch starts with 200 stitches and needs about 300 rows for a 60-inch body, before borders or pattern-repeat adjustments.
Plan the rest of your blanket
If your blanket is made from granny squares, use the square-count guide to choose a layout. Once your dimensions are set, use the Yarn Estimator for the separate quantity, yardage, and skein calculation.
Learn the method
Guides for this calculator