How many increases per round for a flat circle?

For dc (UK)/sc (US): 6 increases per round. For htr (UK)/hdc (US): 8. For tr (UK)/dc (US): 12. For dtr (UK)/tr (US): 16. These numbers correspond to the stitch height ratio and keep the circle flat.

Why does my crochet circle cup or ruffle?

Cupping means too few increases per round - try adding 1-2 more increases. Ruffling means too many increases - reduce by 1-2. Gauge variation is the usual cause. The standard numbers assume average tension; adjust for your own.

Can I use this for oval or elliptical shapes?

This calculator is for circles only. For ovals, use our Oval Calculator which starts with a foundation chain and increases at both ends. The principles are similar but ovals need a different starting structure.

How do I keep increase points from creating a hexagon?

Stagger the starting point of increases each round. Instead of always increasing above the previous increase, offset by 1-2 stitches. Some patterns use invisible increases or random placement for a truly round shape.

What is the maximum size for a flat crochet circle?

There is no theoretical maximum, but very large circles (over 50cm) may start to ruffle slightly as small tension variations accumulate. For large circles, blocking helps flatten the edges. Use stitch markers to track increase positions.

KnitCalcs

Circle Calculator — Flat Crochet Circle Increases

Calculate increases per round for flat crochet circles of any size and stitch type.

Target Diameter

Finished circle diameter

Stitch Type

Stitch height affects increases needed

Stitch Gauge (per 10cm)

Stitches per 10cm from swatch

Row Gauge (per 10cm)

Rows/rounds per 10cm from swatch

How We Calculate This

Flat crochet circles work by adding a fixed number of increases each round to accommodate the growing circumference.

The formula

Rounds = (Diameter / 2) x Row gauge per cm

Increases per round: dc=6, htr=8, tr=12, dtr=16

Final stitch count = Starting stitches + (Rounds - 1) x Increases per round

Frequently Asked Questions

Related Calculators

Crochet Gauge Calculator

Calculate crochet gauge from swatch measurements for any stitch type.

Amigurumi Calculator

Calculate increase and decrease rounds for amigurumi spheres and shapes.

Granny Square Calculator

Calculate number of granny squares and yarn needed for a blanket or garment.

Oval Calculator

Calculate foundation chain and increases for flat crochet ovals.

Crochet Blanket Calculator

Calculate yarn, chain count, and rows for crochet blankets.

Last updated: February 2026

All calculations are estimates based on standard yarn weights and gauge. Results may vary with individual tension, yarn brand, and needle size.