Calculator
Continuous Spiral Crochet Calculator
Crocheting in a continuous spiral — amigurumi, bags, baskets — works in flat-circle math: each round adds a fixed number of stitches. Tell us your starting stitches and target, and we'll tell you how many rounds.
Calculator
How this works
After round 1 (the magic ring or starting circle), every following round adds a fixed
number of stitches — typically 6 to keep the circle flat. So at round R you have
start + (R − 1) × increase stitches. We solve for the smallest R that
meets or exceeds your target.
Why 6 increases per round for a flat circle?
Geometry. A round of crochet adds a fixed amount of circumference, and 6 stitches per round is the rate where the circumference growth matches a flat plane. Fewer than 6 and the work cups inward (good for bowls and bears). More than 6 and it ruffles outward (decorative edges).
- 6 (flat): coasters, hat tops, bag bottoms, mandala motifs. Once a flat hat top is the right diameter, switch to the hat crown decrease calculator to shape it back inward.
- 4–5 (slow curve): amigurumi heads, berets, soft bowls.
- 3 (dome): sphere bases (paired with even rounds and decreases later).
- 8+ (ruffle): decorative flower edges, lettuce hems, doll dresses.
What if my target falls between rounds?
The result shows the round where you'll meet or exceed your target, along with the actual stitch count and how many extra stitches that is. If the overshoot is small (1–3), you can usually skip the increases on the last round to land exactly on target. If you want to stop short, work one fewer round — we tell you what that count would be.
Spiral vs. joined rounds — does this calculator apply?
Yes. The stitch math is the same whether you spiral continuously (no join) or join each round with a slip stitch. Continuous spirals just save you from counting joins and avoid a visible seam.
Tips for clean spiral crochet
- Use a stitch marker at the start of each round — the spiral makes it easy to lose your place after row 3.
- For amigurumi, work into the back loop only on round 2 to give a crisper base.
- For bags and baskets, switch to no increases (just single-crochet straight) once you reach your target diameter — the work will rise vertically.
- If your circle ruffles, you have too many increases; if it cups, too few.