The amigurumi size calculator estimates finished toy diameter from your crochet hook size and yarn weight combination — helping you choose materials to hit a target size or predict how big your current supplies will make the finished plush.
Hook & Yarn Selection
Leave blank to just see estimates for selected hook/yarn
Common Yarn Weight Size Reference
| Yarn Weight | Typical Hook | Amigurumi Size |
|---|---|---|
| Fingering (1) | 2.5 mm | ~4–6 cm (1.5–2.5 in) |
| Sport (2) | 3.0 mm | ~6–9 cm (2.5–3.5 in) |
| DK (3) | 3.5 mm | ~9–13 cm (3.5–5 in) |
| Worsted (4) | 4.0 mm | ~13–18 cm (5–7 in) |
| Bulky (5) | 5.5 mm | ~18–25 cm (7–10 in) |
* Based on standard 6-round magic circle head, average tension. Tight crocheters will make smaller toys.
How to Estimate Amigurumi Finished Size
Amigurumi size is mostly controlled by yarn weight — thicker yarn makes bigger, chunkier toys. Hook size plays a secondary role by tightening or loosening tension. This amigurumi size calculator helps you pick the right combo before buying supplies or starting a pattern.
Step 1: Select your hook and yarn
Choose your crochet hook size in mm and your yarn weight from the dropdowns. The standard amigurumi approach is to use a hook 0.5–1mm smaller than the yarn label recommends — this creates tighter stitches so stuffing doesn't show through. For worsted weight (label says 5mm), use 3.5–4.0mm.
Step 2: Enter a target size (optional)
If you have a target finished size in mind, enter it to see how close your current hook/yarn combination gets you. If you're far off, the calculator suggests which yarn weight and hook combination would better hit your target. A 10cm toy needs fingering or sport weight; a 20cm toy needs worsted or bulky.
Step 3: Account for personal tension
The size estimates assume average tension. If you crochet tightly, your toy will be about 10–15% smaller than estimated. If you crochet loosely, it will be 10–15% larger. Crochet a 6-round magic ring circle and measure its diameter — compare to the expected diameter for your yarn weight to calibrate.
FAQ
Is this amigurumi size calculator free?
Yes, completely free with no signup required. Select your hook and yarn weight for an instant size estimate.
Is my data safe and private?
Yes. All calculations run locally in your browser. No data is sent to any server.
How do I calculate amigurumi size from hook and yarn?
Amigurumi size is mainly determined by yarn weight — thicker yarn makes bigger toys. A worsted weight toy with a 4mm hook is typically 6–8 inches (15–20cm) diameter. Going down in yarn weight (to sport or fingering) reduces size by roughly 30–40%. Tighter tension also reduces size.
What hook size should I use for amigurumi?
Amigurumi needs tight tension to prevent stuffing from showing through. Use a hook 0.5–1mm smaller than the yarn label recommends. For worsted weight (recommended 5mm hook), use 3.5–4mm. Tight stitches = cleaner look and stiffer structure.
Why does my amigurumi come out a different size than expected?
Personal tension varies — some crocheters work tighter or looser than average. The estimates are based on average tension with recommended hook/yarn. Swatch a magic ring + 6 rounds and measure to calibrate. If your gauge is smaller (tighter), your finished toy will be smaller than estimated.
How do I make a bigger amigurumi without changing the pattern?
Go up one yarn weight category (e.g., worsted to bulky) and use the corresponding larger hook. The pattern will work the same — more chains, more rounds, same design — but everything scales up roughly 30–40% per weight category jump.