How the crochet pattern generator works
Hand-calculating amigurumi patterns is tedious. Every sphere follows the same mathematical rule: increase 6 stitches per round until you reach the target circumference, then mirror those decreases to close. This tool automates that calculation so you can skip the math and get straight to crocheting.
The sphere formula
A perfect amigurumi sphere starts with a magic ring of 6 single crochets.
Each subsequent round adds 6 stitches — round 2 has 12, round 3 has 18,
round 4 has 24, and so on. The increase pattern is
round N = 6 × N
stitches. To find how many increase rounds you need, divide your target
stitch count by 6 and round up.
Target stitches = π × diameter × gauge.
So for a 3-inch sphere at 15 stitches per inch, target = 3.14 × 3 × 15 ≈ 141
stitches. That means 24 increase rounds (6 × 24 = 144), then 24 decrease
rounds to close — a 48-round sphere.
Choosing the right shape
Sphere is the most common amigurumi shape — use it for heads, bodies, and any round form. Set the height equal to the diameter for a perfect ball; increase height for an oblong shape (like a rugby ball or egg).
Cylinder adds a straight tube between two half-spheres. Use it for arms, legs, tentacles, or any limb that has a rounded shoulder and wrist. The "height" input controls the straight section only.
Cone starts wide and decreases to a point. Perfect for witch hats, unicorn horns, or Christmas tree shapes. The tool spreads the decreases evenly so the taper looks smooth.
Flat circle has only an increase phase — no straight or decrease rounds. Use it for coasters, rug bases, or the bottom of a basket. The final round's stitch count is your working count for the basket walls.
Getting your gauge right
The single most important input is your gauge — stitches per inch. Two crocheters using the same hook and yarn can produce gauges 30% apart because of tension differences. Always swatch: crochet a 4×4 inch square, count the stitches across, and divide by 4. Enter that number in the gauge field.
For amigurumi specifically, you want a tighter gauge than for garments so the stuffing does not show through. Most amigurumi designers recommend going down one hook size from the yarn label's recommendation. If you cannot swatch, the preset buttons give typical values for common yarn weights.
Limitations and accuracy
This tool generates mathematically correct patterns for basic shapes. It does not account for complex curves (like a teddy bear's snout), color changes, or stitch textures. The yarn estimate is intentionally conservative — actual usage varies by 10–15% depending on tension and stitch type. Always buy a little extra yarn from the same dye lot.
A future version may use AI to generate patterns from uploaded photos — for example, turning a picture of a stuffed animal into a custom amigurumi pattern. This MVP focuses on the rule engine for standard shapes, which covers the majority of amigurumi projects.