Crochet Foundation Chain & Stitch Multiple Calculator

A patterned row only works at stitch counts its repeat allows. This calculator converts your gauge and target width into a raw stitch count, snaps it to the nearest count your pattern accepts, and tells you how many chains to make — including whether the turning chain counts as a stitch.

Calculate your foundation chain

1. Width and gauge
Gauge width follows this: 4 in or 10 cm.
Finished width you want, before any border.
From a blocked swatch worked in the actual stitch pattern.
Usually 4 in or 10 cm. Change it if you measured over a different span.
2. Pattern repeat
The repeat length. Use 1 if the pattern has no repeat.
The stitches added once for the row, not once per repeat.
Commonly 1 for sc, 2 for hdc, 3 for dc. Your pattern decides.
Not assumed. Single crochet rarely counts it; double crochet usually does.

What a stitch multiple actually means

A pattern repeat is a block of stitches that has to complete before the row ends. When a pattern says multiple of 3 + 1, it is describing two different things at once: the repeat itself, which is 3 stitches long, and a single extra stitch that finishes the row and belongs to the row rather than to any one repeat.

That distinction determines which counts work. Ten repeats of 3 gives 30 stitches, plus the extra gives 31. Eleven repeats gives 34. There is no valid count between them, because 32 or 33 stitches would leave the last motif part-finished.

A pattern written as a multiple of 3 plus 1, built from whole repeats of 3 stitches followed by 1 extra stitch. Ten repeats of 3 makes 30 stitches, plus the single extra makes a valid count of 31. Valid counts step by 3: 28, 31 and 34 work, while 29, 30, 32, 33, 35 and 36 leave an incomplete repeat.
The extra stitch is added once for the row, not once per repeat. Valid counts step by the size of the repeat.
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Chains are not stitches

The chain you make and the stitches you end up with are different numbers, and the turning chain is the reason. In single crochet the turn is a single chain that almost never counts as a stitch, so a 31-stitch row needs 32 chains. In double crochet the turn is three chains and usually stands in for the first stitch, so the same 31-stitch row needs 33.

This calculator asks rather than assumes, because the convention belongs to the pattern, not to the stitch. Getting it wrong shifts every row by one stitch and shows up as an edge that leans.

Two cases compared. In single crochet the one-chain turn does not count as a stitch, so 31 stitches needs 32 chains. In double crochet the three-chain turn counts as the first stitch, so 31 stitches needs 33 chains: 30 chains worked into plus the turn standing in for the thirty-first stitch.
Both rows finish 31 stitches wide. Only the chain differs, and only because of how the turning chain is treated.
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You get two valid widths, not one

Gauge rarely lands exactly on a valid count. An 8 inch target at 4 stitches per inch wants 32 stitches, which a multiple of 3 + 1 does not allow. The honest answer is not a single number but a pair: 31 stitches finishing 7.75 in, or 34 stitches finishing 8.5 in.

Which you pick depends on the project. A fitted sleeve or a hat band wants the narrower option. A blanket, scarf or wrap can absorb the extra half inch, and the wider count often sits better against a border. The calculator returns both with the width each finishes at.

An 8 inch target at 4 stitches per inch needs 32 stitches, but a multiple of 3 plus 1 allows only 28, 31 and 34. The nearest smaller valid count is 31 stitches finishing 7.75 inches, a quarter inch narrow. The nearest larger is 34 stitches finishing 8.5 inches, half an inch wide. Bars are drawn to scale.
Bars drawn to scale. Neither option is wrong — they are the two counts the pattern will actually accept.
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The formula

Every figure on this page comes from four steps:

  1. Density. Gauge stitches divided by the width you measured them over, giving stitches per inch or per centimetre.
  2. Raw count. Density multiplied by your target width. Almost never a whole number, and almost never valid.
  3. Valid count. The nearest n × multiple + plus either side of the raw count, with n forced to at least 1.
  4. Chain. Stitches + turning chain length, minus one when the turning chain counts as a stitch.

Where two valid counts sit equally close, the calculator takes the wider one: a piece a little generous can be eased in at the border, while one cut short cannot be let out. That is a CrochetCalc convention, not a rule from anywhere else.

Three worked examples

A scarf, single crochet, multiple of 3 + 1. Target 8 in, gauge 16 sts over 4 in. Density is 4 sts/in, so the raw count is 32. The valid counts either side are 31 (10 repeats + 1) and 34 (11 repeats + 1); 31 is closer. The turn is one chain and does not count, so chain 32 and work 31 stitches, finishing 7.75 in.

A blanket, double crochet V-stitch, multiple of 2 + 1. Target 45 in, gauge 12 sts over 4 in. Density is 3 sts/in and the raw count is 135, which is already valid (67 repeats + 1). The 3-chain turn counts as the first stitch, so chain 137 — 135 + 3 − 1 — and the finished width lands on 45 in exactly.

A metric project, double crochet, multiple of 6 + 2. Target 50 cm, gauge 18 sts over 10 cm. Density is 1.8 sts/cm and the raw count is 90. Valid counts are 86 (14 repeats + 2) and 92 (15 repeats + 2); 92 is nearer. With a counting 3-chain turn, chain 94 and finish at 51.1 cm — about a centimetre over, which a border will hide.

Common crochet stitch multiples

These are the repeats you meet most often. They are a reading aid for pattern notation, not a substitute for the multiple your own pattern states.

Stitch patternTypical repeatExample valid countsUsual turning chain
Plain single crochetmultiple of 1any count1, does not count
Plain double crochetmultiple of 1any count3, usually counts
V-stitchmultiple of 2 + 131, 33, 353, usually counts
Granny stripemultiple of 3 + 128, 31, 343, usually counts
Shell, 5-dcmultiple of 6 + 131, 37, 433, usually counts
Ripple / chevronmultiple of 12 + 327, 39, 51varies by pattern
Moss / linen stitchmultiple of 2 + 131, 33, 351, does not count

Where foundation chains go wrong

Adding the “plus” to every repeat. A multiple of 3 + 1 over ten repeats is 31, not 40. The extra belongs to the row.

Chaining the stitch count exactly. That leaves nothing for the turn, so the first row comes up one stitch short and the edge slants from there.

Measuring gauge on an unblocked swatch, or in the wrong stitch. Density from a plain double crochet swatch will not predict a shell pattern. Swatch in the stitch you intend to use, then block it — the gauge swatch calculator compares your swatch against a pattern's stated gauge.

Forgetting the chain is loose. A foundation chain worked at the same tension as the fabric is usually tighter than the row above it. Many crocheters go up a hook size for the chain alone, or use a chainless foundation row instead.

Frequently asked questions

How many chains do I need for a crochet pattern?

Work out the stitch count first, then add the turning chain. Multiply your gauge in stitches per inch by the width you want, round that to a count your pattern repeat allows, then add the turning chain length — minus one if your pattern counts the turning chain as the first stitch. A 31-stitch row in single crochet needs 32 chains; the same row in double crochet, where the 3-chain turn usually counts as a stitch, needs 33.

What does "multiple of 3 + 1" mean in crochet?

It means the stitch count must divide into whole groups of 3 with exactly 1 stitch left over for the row, so 28, 31 and 34 all work and the numbers between them do not. The extra stitch is added once for the whole row, not once per repeat — that is the step most often got wrong.

Why can't I just chain the number of stitches I want?

Two reasons. The turning chain adds length that is not always a stitch, and a patterned row only works at counts its repeat allows. Chaining the raw number usually leaves a part-finished motif at the end of every row.

Does the turning chain count as a stitch?

It depends on the pattern, which is why this calculator asks rather than assumes. A single crochet turning chain almost never counts. A double crochet turn of three chains usually does. If the pattern does not say, count the stitches in row one and compare.

What if my gauge is between two valid counts?

It usually will be. The calculator returns the nearest valid count below and above your target with the width each one finishes at, so you choose. Narrower suits a fitted piece; wider suits a blanket or wrap.

Is this the same as a stitch count calculator?

No. A stitch count calculator answers how many stitches your dimensions need. This one answers which of those counts your stitch pattern will actually accept, and what to chain to get there.

Sources & further reading

The arithmetic here is arithmetic: density, multiplication and rounding to a permitted count. No standards body publishes stitch multiples — they are properties of individual stitch patterns, which is why the multiple is something you enter rather than something this page claims to know. The common-multiples table is a reading aid drawn from widely used pattern conventions, not a standard.

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