Measure. Make. Piece it together.

Granny Square Blanket Calculator

Turn one blocked square into a blanket plan. Find how many squares fit, allow for joins and a border, and try a numbered color layout you can print and follow.

Your measurements

Measurement unit

Switching units converts your measurements.

The maximum finished width, including your border.

The maximum finished length, including your border.

Measure one square after blocking, before joining.

Extra width between two squares. Use 0 for a join that adds no width.

Measured outward on each of the four sides. Use 0 for no border.

Whole squares only. Your finished blanket will fit within the target dimensions.

Choose your colors

Choose a swatch or type a six-digit hex code. Each color has a number on the layout.

Two colors make a checkerboard. With 3–6 colors, squares sharing an edge have different colors. Counts may vary.

Your assembly plan

Granny square blanket

120whole squares
10 columns × 12 rowsleft to right, top to bottom
50 × 60 inactual finished size

0 in narrower and 0 in shorter than your target.

Target: 50 × 60 in · Square: 5 in · Join: 0 in · Border per side: 0 in

143424143223434241413231213413414312434224143124243232143212132432413131434123244212131212314131314342341412312141432123
Each number matches a color below. Row 1 is at the top. Join and border widths are included in the result, but are not drawn to scale.

Color checklist

Number · hex code · squares
  • Color 1 #C87572 32 squares
  • Color 2 #759B89 28 squares
  • Color 3 #EADDC9 29 squares
  • Color 4 #44576D 31 squares

Square counts are not yarn quantities. Estimate yarn from a blocked sample using your yarn, hook, and stitch pattern; allow separately for joins and the border.

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How to plan your granny square blanket

  1. 01 / Measure

    Start with a blocked square

    Make a sample in your intended yarn and hook size, block it as you will the blanket, and measure the edge before joining. Enter the finished blanket's maximum width and length.

  2. 02 / Allow

    Measure the join and border

    Join two sample squares. Any width beyond twice one square's edge is the added join width. Enter the border's outward width on one side. Use zero where nothing is added.

  3. 03 / Assemble

    Choose colors and print

    Read the actual finished dimensions before you begin. Pick 2–6 distinct colors, rearrange the layout, and print the numbered plan and color checklist for your project bag.

The whole-square formula

This planner chooses the largest number of whole squares that fits within each target dimension. It rounds the count down, so the blanket may finish smaller than your target.

Columns = floor((W − 2B + J) / (S + J))

Rows = floor((L − 2B + J) / (S + J))

Total squares = columns × rows

Finished width = columns × S + (columns − 1) × J + 2B

Finished length = rows × S + (rows − 1) × J + 2B

Geometry is calculated in centimeters before converting the display. Display rounding does not change the square count. If one square plus the border cannot fit, the planner shows an error. Preview limits: 50 rows, 50 columns, and 1,600 squares.

What each measurement means

W and L — target width and length
Maximum outside dimensions of the finished blanket, including its border.
S — blocked square size
The edge length of one finished, blocked square before its join is added. All squares are assumed to have the same size.
J — added join width
Extra width at each seam between neighboring squares. For a join adding no width, use 0. If your square measurement already includes joining allowance, do not add it again here.
B — border on each side
The width extending outward from the square grid on each of its four sides. A 5 cm border adds 10 cm to both overall dimensions.

Three worked examples

A simple 120 × 150 cm blanket

Target 120 × 150 cm; square 10 cm; join 0 cm; border 0 cm.

12 columns × 15 rows = 180 squares. Finished size: 120 × 150 cm.

Width: 12 × 10 = 120 cm. Length: 15 × 10 = 150 cm.

Allowing for joins and a border

Target 120 × 150 cm; square 10 cm; join 0.5 cm; border 5 cm on each side.

10 columns × 13 rows = 130 squares. Finished size: 114.5 × 146 cm.

Width: 100 + 9 × 0.5 + 10 = 114.5 cm. Length: 130 + 12 × 0.5 + 10 = 146 cm. The blanket is 5.5 cm narrower and 4 cm shorter than the target.

The same plan in inches or centimeters

Target 50 × 60 in; square 5 in; join 0 in; border 0 in.

10 columns × 12 rows = 120 squares. Finished size: 50 × 60 in.

Switch to centimeters: target 127 × 152.4 cm, square 12.7 cm. You still need 10 columns × 12 rows = 120 squares.

Before you start making squares

The color checklist counts whole squares in each color; it does not estimate yarn weight or yardage. If your squares use multiple colors within each square, treat each tile color as a square design label. Yarn use needs a real sample in the same stitch pattern, yarn, and hook, plus separate allowances for joining and the border.

Two colors alternate as a checkerboard. Three or more colors never repeat on squares sharing an edge; diagonals may match. Color counts can differ, and a small layout may not use every selected color. Recheck your sample if your joining method, blocking, or tension changes.

The geometry above follows the measurement definitions stated on this page. For related planning workflows, see the CrochetPatterns layout planner and StitchCalc granny square calculator. Their input conventions may differ; use this page's definitions with this calculator.

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