Granny Square Calculator: How Many Squares for Any Blanket Size

📅 Last updated: February 2026
Sarah Mitchell
CYC Certified Instructor · 20+ Years Crochet Experience

I've made over 40 granny square blankets in my career — from baby blankets with 12 squares to king-size throws with 300+. This calculator reflects the real-world math I use every time.

✅ Fact-Checked📋 Editorial Standards
🎯 Key Takeaway: To find how many granny squares you need, divide your blanket width by the square size to get columns, divide height by square size to get rows, then multiply: columns × rows = total squares. A 50×60" throw with 6" squares needs 80 squares plus a 2-inch border.

The granny square is one of the most iconic and versatile motifs in crochet history. Dating back to the early 19th century, this classic motif remains a favorite because of its simplicity, portability, and endless design possibilities. Whether you're joining vibrant scrappy squares for a bohemian throw or crocheting elegant solid-color blocks for a modern baby blanket, the math for planning a granny square blanket is always the same — and our calculator handles it instantly.

In my experience, the biggest challenge with granny square projects isn't the crocheting — it's the planning. How many squares do you actually need? How much yarn should you buy? What layout looks best for a 50×60 inch throw? These are the questions I answer for my students every week, and after making over 40 granny square blankets myself, I've refined the process down to a simple formula that accounts for square size, blanket dimensions, border width, and joining method.

Our granny square calculator below handles all of this. Enter your desired blanket size, your square dimensions, and an optional border width, and you'll get the exact number of squares, the grid layout, estimated yarn per square, total yarn needed, and even how many skeins to buy. Think of it as your project planning assistant — so you can focus on the fun part: choosing colors and crocheting.

Calculate Your Granny Square Layout

Your Granny Square Layout

—
Total Squares
—
Grid (W × H)
—
Actual Size (in)
—
Total Yards
—
Skeins Needed
—
Border Yards
💡 Pro Tip: Buy 1–2 extra skeins for joining squares and borders. If using multiple colors, plan your color layout on paper first — it saves time and prevents running short on any single color.

Common Granny Square Blanket Sizes

Planning your granny square blanket starts with choosing the right finished size. The table below shows standard blanket dimensions from the Craft Yarn Council alongside how many 6-inch granny squares each requires — with and without a 2-inch border.

Blanket Type Size (inches) 6" Squares (no border) 6" Squares (2" border)
Baby Blanket 30 × 36 30 (5×6) 20 (4×5)
Stroller/Car Seat 36 × 42 42 (6×7) 30 (5×6)
Throw Blanket 50 × 60 80 (8×10) 63 (7×9)
Twin Bed 66 × 90 165 (11×15) 130 (10×13)
Full/Double 80 × 90 195 (13×15) 156 (12×13)
Queen Bed 90 × 100 255 (15×17) 210 (14×15)
King Bed 108 × 100 306 (18×17) 272 (17×16)

Yarn Estimates per Granny Square by Size

Square Size Worsted Yarn (yards) DK Yarn (yards) Bulky Yarn (yards)
4 inches 8–12 10–14 6–9
6 inches 18–22 20–26 14–18
8 inches 30–38 35–42 24–30
10 inches 45–55 50–62 36–44
12 inches 60–75 68–82 50–60

How to Join Granny Squares: 5 Methods Compared

After crocheting all your squares, you'll need to join them together. Each joining method creates a slightly different look and affects the final blanket size. Here are the five most popular methods I've used across dozens of projects, ranked by ease and appearance.

1. Whip Stitch Join — The simplest method. Thread a yarn needle and sew through the back loops of both squares held together. Creates an almost invisible seam on the right side. Best for beginners and solid-color blankets where you want clean lines.

2. Single Crochet Join — Hold squares wrong sides together and single crochet through both layers. Creates a visible ridge on the right side that adds a decorative texture. Adds approximately ¼ inch between squares, so factor this into your blanket size calculation.

3. Slip Stitch Join — Similar to single crochet but flatter. Creates a thin, subtle ridge. Faster than SC join but not quite as decorative. A good middle ground between invisible and textured.

4. Mattress Stitch — An invisible seaming technique borrowed from knitting. Sew through the side bars of stitches on each square, pulling them together. The seam disappears completely. Takes the most time but produces the most professional result.

5. Join-As-You-Go (JAYG) — Connect squares during the last round of crocheting each one, eliminating separate seaming. The fastest method overall since there's no assembly step. Requires more planning upfront as you must work squares in a specific order.

💡 Border Tip After joining, add 2–3 rounds of single crochet around the entire blanket to even out the edges, followed by a decorative border of your choice. Shell stitch, granny stitch border, and reverse single crochet (crab stitch) are my three favorites for framing granny square blankets.

Frequently Asked Questions

Divide blanket width by square size for columns, divide height by square size for rows, then multiply. A 50×60" throw with 6" squares: 8 columns × 10 rows = 80 squares. Subtract the border width first if adding a border — with a 2" border, you'd need 7×9 = 63 squares instead.
6-inch squares are the most popular for blankets — they're large enough to show off stitch patterns but small enough to be portable for on-the-go crocheting. 4-inch squares create a finer patchwork, while 12-inch squares are faster to assemble with fewer joins.
A basic 6-inch granny square in worsted weight uses about 18–22 yards. Multi-color squares may use slightly more due to color changes. Make one test square with measured yarn to get your exact yardage — it's the most accurate approach.
For beginners, whip stitch is easiest. For speed, join-as-you-go (JAYG) eliminates separate sewing. For the most professional look, mattress stitch creates an invisible seam. Single crochet join adds a decorative ridge between squares.
Yes, if your squares are different sizes. Even small variations of ¼ inch compound across a blanket. Wet block or steam block all squares to uniform size before joining. Pin them to a blocking mat at the exact dimensions for consistent results.

📚 Sources & References

  1. Craft Yarn Council — Standard Yarn Weight System & Blanket Sizing
  2. Margaret Hubert — "The Granny Square Book" (Creative Publishing, 2nd Edition)
  3. Shelley Husband — "200 Crochet Blocks for Blankets, Throws and Afghans" (David & Charles)
  4. Crochet Guild of America — Joining Techniques Reference Guide

Related Calculators & Guides

🛏️ Blanket Size Calculator🧶 Yarn Yardage Calculator📖 Granny Square Planning Guide