Crochet Granny Square Calculator
Created by: James Porter
Last updated:
Plan your granny square project from start to finish. Enter your target dimensions, choose the number of rounds per square and yarn weight, and get the exact number of squares needed, yarn per square, total yardage, and layout grid — including optional border calculations.
Crochet Granny Square Calculator
CrochetCalculate squares needed, yarn per square, and total yardage for your project
Project Dimensions
Square Setup
Border (Optional)
Related Calculators
What is a Granny Square Calculator?
A Granny Square Calculator helps you plan projects made from individual crocheted squares. It calculates how many squares you need, how large each square will be based on your round count and gauge, and how much yarn the entire project requires.
Granny squares are one of the most versatile crochet motifs — they can be combined into blankets, bags, garments, and home décor. Because each square is worked individually, planning the layout and yarn needs in advance prevents running out of yarn or ending up with too many leftover squares.
Granny Square Formulas
Square Size: Each round adds approximately 2 × (stitch height) to the side length
Squares per Row: ⌈Project Width ÷ Square Size⌉
Number of Rows: ⌈Project Length ÷ Square Size⌉
Total Squares: Squares per Row × Number of Rows
Yarn per Square: Increases with each round — round N uses approximately 4 × (N × 3) cluster stitches worth of yarn
Total Yarn: Yarn per Square × Total Squares + Joining Allowance
Granny Square Calculation Example
You want a 50 × 60 inch throw blanket using 4-round granny squares in worsted-weight yarn with a gauge that produces 6-inch squares.
- Squares per row = ⌈50 ÷ 6⌉ = 9 squares (54 inches actual width)
- Number of rows = ⌈60 ÷ 6⌉ = 10 rows
- Total squares = 9 × 10 = 90 squares
- Yarn per square ≈ 20 yards (4 rounds, worsted weight)
- Base yarn = 90 × 20 = 1,800 yards
- Joining allowance (10%) = 180 yards
- Total yarn ≈ 1,980 yards
Common Applications
- Blankets & Throws — the classic granny square project, from baby blankets to king-size bedspreads
- Bags & Totes — structured bags assembled from squares with a lining
- Garments — cardigans, vests, and ponchos assembled from granny squares
- Cushion Covers — pillow covers using a grid of smaller squares
- Scrap-Busting — use leftover yarn from multiple projects in multi-colour granny squares
Tips for Accurate Results
- Block all squares before measuring — unblocked squares are smaller and uneven.
- Make a test square first to verify your actual size matches the calculated size.
- Add 5–10% extra yarn for joining, borders, and colour changes.
- Keep consistent tension across all squares — even small differences add up over dozens of squares.
Frequently Asked Questions
How many granny squares do I need for a blanket?
Divide the blanket width by the square size to get squares per row, then divide the blanket length by the square size to get the number of rows. Multiply the two numbers together for the total. For a 50 × 60 inch throw with 6-inch squares, you need 8 × 10 = 80 squares.
What size should a granny square be?
Granny square size depends on your yarn weight and number of rounds. A 3-round worsted-weight granny square is typically 4–5 inches. A 5-round square reaches 7–9 inches. This calculator computes exact size from your round count and gauge.
How much yarn does a granny square use?
A standard 3-round granny square in worsted-weight yarn uses roughly 12–18 yards. Larger 5-round squares can use 30–45 yards each. Multi-colour squares use less of each colour but the same total. Enter your details above for a precise per-square and total yarn estimate.
How do I join granny squares together?
Popular joining methods include slip-stitch join, single-crochet join, whip stitch, and the join-as-you-go (JAYG) technique. Slip-stitch join creates a flat seam; single-crochet join adds a decorative ridge. Allow 1–2 extra yards per square for joining.
Can I make granny squares different colours?
Yes — multi-colour granny squares are one of the most popular crochet designs. Change colour at the end of each round by fastening off and joining the new colour, or carry the yarn along. Plan roughly equal yardage divided among your chosen colours.
Sources and References
- Craft Yarn Council, "Standard Yarn Weight System & Gauge Ranges", 2024
- The Crochet Guild of America, "Granny Square Techniques & Variations"
- Ravelry Community, "Granny Square Blanket Sizing Data", 2024