Start every project with the right numbers: a starting chain with its turning chain counted, stitch counts from your own gauge, and increases or decreases spread evenly, written out ready to hook. The counts work for a scarf, a garment, or anything else your hook starts.
Hook a swatch at least 6 in square in your project stitch, block or wash it, then count across the middle 4 inches.
Direction
Chain
121chains
for a row of 120 sc
Chain 121, then work your first sc into the 2nd chain from the hook.The 1 skipped chain stands in for the turning chain.
- Stitches in row 1120
- Turning chain1
- Chains to make121
The Formulas
Starting Chain
chains = stitches + turning chain · sc +1, hdc +2, dc +3, tr +4The extra chains stand in for the height of the first stitch. You work the first stitch into the chain that leaves the turning chains skipped, the 2nd chain from the hook for sc, the 4th for dc.
Stitches from Gauge
stitches = width × (stitches counted ÷ inches measured)Shaping Spread Evenly
decrease: plain between = (stitches − 2 × decreases) ÷ decreases · increase: plain between = (stitches − increases) ÷ increasesA sc2tog uses two stitches; working 2 sc into one stitch uses one. That one-stitch difference is why crochet increase rows and knitting increase rows count differently.
Worked Example
An amigurumi round of 60 stitches decreasing to 54, in the round. Six sc2tog, each using 2 stitches, leaves 48 plain:
- 48 ÷ 6 = 8 plain stitches between decreases, no remainder.
- Written out: [Sc 8, sc2tog] × 6. Count after the round: 54.
- The same row flat places the leftovers at the row ends, so the taper stays centered on a blanket edge or a sleeve seam.
Turning Chains and Crochet Gauge by Yarn Weight
| Stitch | Turning chain | First stitch goes in |
|---|---|---|
| Single crochet (sc) | 1 | 2nd chain from hook |
| Half double (hdc) | 2 | 3rd chain from hook |
| Double crochet (dc) | 3 | 4th chain from hook |
| Treble (tr) | 4 | 5th chain from hook |
Single crochet gauge the Craft Yarn Council publishes per weight, stitches per 4 inches:
| Weight | Sc per 4 in | Usual hooks |
|---|---|---|
| 1 · Super fine | 21–32 | B-1 to E-4 (2.25–3.5 mm) |
| 2 · Fine (sport) | 16–20 | E-4 to 7 (3.5–4.5 mm) |
| 3 · Light (DK) | 12–17 | 7 to I-9 (4.5–5.5 mm) |
| 4 · Medium (worsted) | 11–14 | I-9 to K-10½ (5.5–6.5 mm) |
| 5 · Bulky | 8–11 | K-10½ to M-13 (6.5–9 mm) |
| 6 · Super bulky | 7–9 | M-13 to Q (9–15 mm) |
| 7 · Jumbo | 6 or fewer | Q and up (15 mm +) |
How to Measure Your Inputs
- Swatch in the project stitch. Double crochet fabric runs taller and looser than single crochet from the same hook and yarn; their gauges aren’t interchangeable.
- Count across the middle 4 inches with the swatch flat and relaxed, edges excluded.
- For the starting chain, chain loosely or go up a hook size for the foundation: a tight chain pulls the whole bottom edge narrower than your gauge promised.
Assumptions and Defaults
- The turning chain here does not count as a stitch: today’s most common convention. Many patterns, mostly older dc patterns, count the ch-3 as the first dc; follow your pattern when it says so, and chain one less.
- Shaping writes sc2tog and “2 sc in next st”; the spacing holds for hdc and dc shaping too.
- Worked flat, leftover plain stitches sit at the two row ends; in the round they spread across the repeats.
- Stitch counts from gauge round to the nearest whole stitch.
Crochet Math Questions, Answered
How do I calculate my starting chain?
To calculate a starting chain, decide how many stitches the row needs and add the turning chain for your stitch: one for sc, two for hdc, three for dc, and four for tr. A 120-sc row therefore starts with 121 chains, with the first sc worked into the second chain from the hook, and if you know the width and gauge instead, the chain tab calculates the count from those.
How many chains do I need for a blanket?
A blanket needs its width times your stitches per inch, plus the turning chain, so a 50 in blanket at 3 sc per inch starts with 151 chains. Crochet a gauge swatch first, because estimating gauge from the yarn label alone can miss by an inch or more across a blanket.
How do I decrease evenly in crochet?
To decrease evenly in crochet, remember that each sc2tog uses two stitches, so you spread (stitches − 2 × decreases) ÷ decreases plain stitches between them. Going from 60 to 54 stitches in the round works out to [sc 8, sc2tog] × 6, and the shaping tab writes the row for any pair of counts.
How do I increase evenly in crochet?
To increase evenly in crochet, remember that an increase is two stitches worked into one, so it uses one stitch of the row below, and you spread (stitches − increases) ÷ increases plain stitches between them. Going from 60 to 66 stitches works out to [sc 9, 2 sc in next st] × 6, repeated around the row.
What crochet hook size do I use for my yarn?
The right hook size for your yarn starts with the label; without one, match the weight class in the chart above, where worsted takes an I-9 to K-10½ hook. After that, let the fabric guide you: go up a size if it feels stiff, and down a size if it feels loose.
Why is my starting chain tighter than my rows?
Most crocheters chain more tightly than they crochet, which makes the bottom edge pull in. Chain with a hook one size larger, or chain loosely on purpose, and the edge will lie flat; foundation single crochet avoids the problem altogether by building the chain and the first row at the same time.
Gauge and hook ranges: Craft Yarn Council yarn weight standards.