How to use the crochet chain length calculator
- Choose inches or centimeters and enter the finished width you want.
- Enter your stitches per unit from a swatch, matching the unit above.
- Add any turning chains your first row needs. In More options, set a stitch pattern repeat and any extra stitches if your pattern needs a multiple.
- Read the headline for the foundation chain, and the table for chain counts one or two repeats either side.
Formula
exact stitches = width x stitches per unit
with a repeat: stitches = round((exact - extra) / repeat) x repeat + extra
foundation chain = stitches + turning chains
Without a repeat, the stitch count is rounded to the nearest whole stitch. The finished width with the chosen count is stitches divided by stitches per unit.
30 inches at 4 stitches per inch
30 x 4 = 120 stitches, so the foundation chain is 120 with no turning chain. The width with that count is exactly 30 inches, or 76.2 centimeters.
For a pattern that is a multiple of 6 plus 1, at 3.5 stitches per inch: the exact count is 30 x 3.5 = 105, and (105 - 1) / 6 = 17.33 rounds to 17 repeats, so 17 x 6 + 1 = 103 stitches. With one turning chain, the chain is 104, and the width is 103 / 3.5 = 29.43 inches, 0.57 inch narrower than wanted. In centimeters, 76.2 cm at 1.6 stitches per cm is 121.92, rounded to 122.
Measuring your gauge
Gauge is how many stitches you make per inch with a given yarn, hook and tension. Work a swatch at least 4 inches square in the stitch you plan to use, lay it flat without stretching, and count the stitches across a measured width. Divide the stitches by the width to get stitches per unit. A small difference in gauge becomes a large one over a wide piece.
A chain row is often tighter or looser than the fabric above it, so the foundation chain may not measure the width you expect. Follow your pattern for how to start, and treat the count here as the stitches the fabric needs.
Pattern repeats and related tools
Many stitch patterns repeat across a row, so the stitch count must be a multiple of the repeat, sometimes plus a few edge stitches. Rounding to a whole repeat can shift the width slightly, and the page shows how far. For yarn quantity, the Yarn Yardage Calculator helps, and the Knitting Gauge Calculator covers the same idea for knitting.
Assumptions and limits
- Your gauge is the same across the whole piece. Real tension varies and a swatch is only a sample.
- Turning chains and stitch repeats come from your pattern. Nothing is assumed about the stitch.
- The pattern repeat and extra stitches are whole numbers. A repeat of 1 and 0 extra means no rounding to a pattern.
- Counts are rounded to the nearest whole stitch or repeat.
Frequently asked questions
How many chains do I need to start a crochet project?
Multiply the width you want by your stitches per inch, then add any turning chains. At 4 stitches per inch, a 30 inch piece needs 120 chains. Your gauge from a swatch gives the best number.
What is a stitch pattern multiple?
Some stitch patterns repeat a fixed number of stitches, such as a multiple of 6 plus 1. The chain must fit the repeat, so enter the repeat and extra stitches and the page rounds the count to the nearest fit.
Why is my chain a different width than expected?
The chain row is often tighter or looser than the fabric, and the width of the finished piece depends on your tension in the stitch you use. Measure your swatch in the stitch rather than the chain.
How do turning chains change the count?
They are extra chains at the start of a row that bring the work up to the height of the first stitch. The page adds the number you enter to the stitches, since they do not count toward the width.