Amigurumi Size Calculator: Finished Size From Yarn, Hook and Rounds

Want to know how big a toy will be before you crochet it, or how to make a pattern bigger or smaller? Choose your yarn weight and hook, then enter the stitch count of the widest round. The calculator estimates the finished diameter and works backward from a target size. If you have measured your own gauge, enter it for a much closer answer.

Palm size amigurumi: kits and comfortable hooks

Toys 2 to 5 inches across are the classic amigurumi size. A kit teaches the shaping, and a cushioned hook makes tight single crochet easier on the hands.

Beginner

The Woobles

The Woobles Beginner Crochet Kit Bundle (Penguin, Chick, Fox, Bunny)

$99.99

Four beginner kits (penguin, chick, fox and bunny) with pre started yarn and video tutorials.

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Beginner

Clover

Clover Quick Locking Stitch Marker Set

$12.96

Mark the first stitch of every round so spiral rounds never lose count.

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Expert

Tulip

Tulip Etimo Rose Crochet Hook Set

$109.99

Ten cushion grip hooks from 2 to 6 mm, covering the small sizes amigurumi uses.

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Prices change often, so confirm on Amazon. As an Amazon Associate we earn from qualifying purchases.

How do you calculate amigurumi size?

Most amigurumi are built from spiral rounds of single crochet that grow by a fixed number of stitches each round, then work even, then decrease. The widest round sets the size, and turning it into inches takes two formulas.

1. Circumference = stitches in the widest round / stitches per inch. With 36 stitches at 4.81 stitches per inch: 36 / 4.81 = 7.48 inches around.
2. Diameter = circumference / pi. 7.48 / 3.1416 = 2.38 inches across, or 6 cm.

Working backward for a target size flips the formulas: stitches = diameter x pi x stitches per inch. For a 3 inch ball, 3 x 3.1416 x 4.81 = 45.4 stitches. Rounds grow in steps of 6, so the calculator rounds to 48 stitches, reached after 8 rounds, which comes out about 3.2 inches.

Where does the stitches per inch estimate come from?

This is the part to treat with care, because it is an approximation. The Craft Yarn Council publishes a single crochet gauge range for each yarn weight, and it pairs the tightest gauge with the smallest recommended hook. For medium weight yarn that is 14 stitches per 4 inches, or 3.5 per inch, on a 5.5 mm hook.

Amigurumi is worked on smaller hooks than that. The calculator assumes a stitch's width shrinks in proportion to the hook, so it scales the tightest gauge by the ratio of hook sizes: 3.5 x 5.5 / 4 = 4.81 stitches per inch on a 4 mm hook. Real stitches do not scale perfectly, and tension varies from one crocheter to the next, so the estimate can easily be off by a noticeable amount.

To get a reliable number, crochet the first 6 or 7 rounds of a flat circle with your yarn and hook, lay it flat without stretching, and measure across. Divide the last round's stitch count by (the diameter x 3.1416) and type that into the stitches per inch box. The calculator then uses your gauge instead of the estimate.

How big is a 36 stitch round in each yarn weight?

This table uses each weight's tightest CYC single crochet gauge at its smallest recommended hook, so no hook scaling is involved. Because amigurumi normally uses a smaller hook than these, expect real toys to come out somewhat smaller than the figures shown.

The spread is the useful part. The same pattern crocheted in super bulky yarn is more than three times the diameter of the super fine version, which is why changing yarn is the easiest way to resize a toy without rewriting a single round.

Amigurumi size by round, in worsted on a 4 mm hook

Each round of a 6 stitch start adds 6 stitches, so round 6 has 36 and round 10 has 60. Sizes use the estimated 4.81 stitches per inch; if you have measured your own, the calculator above gives exact figures.

A ball's height is set by its rounds rather than its stitches, and single crochet rows are shorter than they are wide, so patterns add even rounds between the increases and decreases to make the shape round. For the exact instruction on every increase round, the increase or decrease evenly calculator writes it out in single crochet.

How do you measure an amigurumi that is not a ball?

Most toys are a set of simple shapes: a ball for the head, an egg or cylinder for the body, and small tubes for arms and legs. The same formula works for each part. Find the widest round of that piece in the pattern and run it through the calculator to get its diameter. A cylinder, such as a body worked even for many rounds, stays at that diameter for its whole height. An egg shape is widest at one round and tapers on both sides, so the widest round still gives its greatest width.

Height is harder to predict than width, because it depends on row gauge, which the stitch count alone does not tell you. The easiest way to plan height is to count the rounds in the pattern and measure a few rounds of your own swatch circle from the side. Add a little for the stuffed curve of each piece.

How do you resize an amigurumi pattern?

• Change yarn and hook together. The pattern stays the same and every measurement scales. It is the most reliable method, as the weight table shows.
• Add or remove increase rounds. Adding one increase round, one even round and one decrease round makes a ball a little larger. This changes the proportions of limbs and heads, so it suits simple shapes best.
• Stuff differently. Firm stuffing stretches the fabric slightly and rounds out the shape; light stuffing keeps it softer and a touch smaller. It will not rescue a big size difference.

Small amigurumi are also where good light earns its place. Counting stitches in a spiral of dark yarn is tiring, and a magnifier such as the Daylight Halo Go 2, with 2.25x and 4x lenses, helps with tiny pieces. For learning the shaping, a kit like the Woobles 4-Kit Bundle includes pre started yarn and video lessons. Start with a magic ring and single crochet if either is new to you.