Crochet C2C Blanket Calculator

Use a measured corner-to-corner block sample to estimate how many C2C blocks you need across and down for a rectangular blanket or panel.

Scope: this models a classic rectangular C2C block grid. It does not estimate yarn or account for a separately added border. Use a sample made with the same yarn, hook and C2C stitch method as the project.

How it works

Average block width = measured sample width ÷ blocks across. Average block height = measured sample height ÷ blocks down. The target dimensions are divided by those block dimensions and rounded to whole blocks.

Classic C2C row phases

For a rectangular grid, the classic diagonal construction has an increase phase equal to the shorter block dimension, a rectangular maintain phase equal to the difference between the long and short dimensions, and a decrease phase of one fewer row than the shorter dimension.

Check your sample

C2C blocks can change size with yarn, hook, stitch variation and tension. Measure several blocks rather than a single block when possible.

Worked example

If 5 C2C blocks measure 25 cm across and 25 cm high, the measured average block is 5 cm square. A 100 × 150 cm target therefore needs 20 × 30 blocks when rounding up: 600 blocks in total and 49 classic diagonal rows.

Common question

Does this calculate yarn? No. It calculates the block grid and diagonal-row phases. Use a representative swatch and the Crochet Yarn Calculator for a separate yarn estimate.

Related crochet tools

Granny Square Calculator · Crochet Yarn Calculator · Yarn Skein Calculator