How to use this calculator
Make a complete sample granny square, including the same round count and hook you plan to use. Measure its finished size after blocking. Enter your blanket dimensions and yarn used per square. Use the estimated count and visual layout as a starting plan.
Frequently asked question
Does the yarn estimate include joins and borders? No. The yarn estimate here counts only completed squares. Add a separate allowance based on the joining technique, border and tension.
Crochet planning guide
Calculate how many granny squares you need
Divide the planned blanket width by the finished width of one square, and do the same for height. Round up to whole squares. Multiply columns by rows for the total. For example, a 120 × 150 cm blanket with 15 cm squares requires 8 columns × 10 rows = 80 squares.
Account for joining and borders
Measure squares after blocking. Joining seams and borders can change the final dimensions. If your chosen joining method adds width, adjust the square count before committing to a layout.
Plan colours before you crochet
Choose a repeatable colour distribution and record how many squares each colour needs. Make one complete sample square and weigh or measure its yarn use before purchasing supplies.
Avoid common planning errors
Square dimensions vary with yarn, stitch tension and blocking. Do not assume all granny squares have the same finished dimensions, especially when mixing stitch patterns.
Common questions
Do granny squares need blocking?
Blocking can help squares reach consistent dimensions, depending on the fibre and pattern.
Does the calculator include borders?
Treat border yarn and dimensions as additional allowances unless your inputs explicitly include them.