Blanket size calculator
Turn a target size into cast-on stitches and rows at your gauge.
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 and edge finishing. This gives the blanket's main body size; add any border or edging separately.
- 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 4 August 2026Found a wrong number? Tell us.
How to use this
- Enter the finished dimensions you want for the blanket's flat body, not including extra border width.
- 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.
Next step
If your blanket is made from granny squares, or you want to plan a join layout, try the granny-square calculator instead.