Foundation chain calculator

A foundation chain has to give the right width, fit the stitch pattern's repeat and allow for the turning chain. This calculator does all three, writes out how to start row 1, and shows the narrower, closest and wider options so you can choose.

How to use the foundation chain calculator

1. Choose inches or centimetres and US or UK terms.
2. Enter the width you want, before any border, and your stitch gauge over 4 in (10 cm), measured in the pattern stitch.
3. Enter the stitch repeat from the pattern, such as multiple of 6 plus 2. For plain rows, use 1 and 0; the form starts with 6 and 2 as an example.
4. Add edge stitches if you want plain stitches at each side of the pattern.
5. Choose the first-row stitch and whether the turning chain counts as a stitch. Leave it on the usual rule unless your pattern says otherwise.
6. Choose a starting chain or a chainless foundation, and pick narrower, closest or wider rounding.

How the calculator works

Width × gauge gives the raw stitch count. After taking off any edge stitches and the "plus" stitches, the rest is divided by the multiple and rounded to a whole number of repeats:

Repeats = (stitches − edge stitches − plus) ÷ multiple, rounded

First row = multiple × repeats + plus + edge stitches

Then the turning chain is added: 1 chain for sc, 2 for hdc, 3 for dc and 4 for tr. When the turning chain counts as the first stitch (usual for dc and taller), one fewer chain is needed, because the skipped chains stand in for that stitch:

Chains = first-row stitches + turning chain − 1 if it counts as a stitch

With a chainless foundation (fsc, fdc) there is no separate chain: you work the first-row stitches directly.

Reading your results

• Chains to make: the number to chain.
• Stitches in the first row: with the number of repeats, so you can check against the pattern.
• Start like this: the first two lines written out, including which chain from the hook to work into.
• Narrower, closest and wider: the three counts that fit your repeat, with the width each one makes.

Worked example

A 50 in blanket in a shell pattern worked over a multiple of 6 plus 2, starting with a row of double crochet, at 14 stitches per 4 in (3.5 per inch):

• Raw stitches: 50 × 3.5 = 175.
• Repeats: (175 − 2) ÷ 6 = 28.83, rounded to 29.
• First row: 6 × 29 + 2 = 176 dc.
• Chains: 176 + 3 − 1 = 178, because the 3 skipped chains count as the first dc. Work the first dc in the 4th chain from the hook.
• The blanket comes out 176 ÷ 3.5 = 50.29 in wide. The narrower option is 170 dc (172 chains), 48.57 in wide.

US and UK terms

Switch the calculator to UK terms and every stitch name in the results changes; the numbers stay the same. UK names are one step taller than US names for the same stitch:

• US single crochet (sc) = UK double crochet (dc)
• US half double crochet (hdc) = UK half treble (htr)
• US double crochet (dc) = UK treble (tr)
• US treble (tr) = UK double treble (dtr)

The turning chain follows the stitch's height, so a UK treble (US dc) also uses 3 chains.

Accuracy and limits

• The arithmetic is exact and covered by our automated tests. It assumes your gauge was measured in the pattern stitch.
• At least one full repeat is always used. If one repeat is already wider than your target, the calculator warns you.
• If the pattern's plus is as big as its multiple or bigger, check whether it already includes the turning chain; the calculator reminds you.
• Borders are not included. Take the border width off before you enter the width.

Common mistakes

1. Counting the loop on the hook. It is not a chain. Start counting with the first chain below the hook, both when you count the chain and when you count back to "4th chain from hook".
2. Leaving the sample repeat on for plain rows. Set the multiple to 1 and plus to 0.
3. Twisting a long chain. Before row 1, check the chain lies flat. Working into the back bumps keeps it from twisting and gives a neat bottom edge.

Tips for more accurate results

• Foundation chains are often tighter than the rows above. Chain with a hook 0.5 mm larger, or use a chainless foundation such as foundation double crochet (linked below).
• Clip a stitch marker into every 20th chain so you only recount from the last marker.
• On a very long chain, a couple of spare chains do no harm: work row 1 to the right stitch count and undo the extra chains from the tail.
• For ripples and chevrons, measure gauge across the finished wave, not along the slope. Measure gauge first with the gauge calculator.

Frequently asked questions

Related guides and tools

• Skip the chain with foundation double crochet