Hat Crown Increase Calculator
Tell it how wide the crown needs to be and how your stitch grows — get the full round-by-round stitch count table.
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How the crown increase calculator works
- Rounds build the radius. Rounds = crown diameter x rounds gauge ÷ 2. A 6.3-inch crown at 6 rounds per inch needs 6.3 x 6 / 2 = 18.9, rounded to 19 rounds.
- Stitch count = family x round. With 8 stitches per round, round 1 has 8 stitches, round 2 has 16, and round 19 ends with 19 x 8 = 152 stitches.
- Check the diameter. 19 rounds at 6 rounds per inch gives a diameter of 2 x 19 / 6 = 6.33 inches — a hair over target, which is the rounding you should expect.
Crown increase FAQ
How do crown increases work in a crochet hat?
The crown is a flat circle: you start with a fixed number of stitches (the "family") and add that same number every round. Six double crochets grow to 12, 18, 24, and so on. The circle widens by the same amount each round, which is what keeps it flat.
Which increase number should I pick?
Match it to your stitch: 6 per round for double and treble crochet, 8 for half double, and 10 to 12 for single crochet or tight amigurumi. The wrong number makes the crown cup or ruffle — cupping means too few increases, ruffling means too many.
Why is rounds equal to diameter times gauge divided by two?
Each round adds one gauge-unit of height, and rounds stack outward from the center to form the crown radius — not the diameter. So diameter = 2 x rounds / gauge, flipped to rounds = diameter x gauge / 2. A 6.3-inch crown at 6 rounds per inch needs 19 rounds.
What do I do after the increase rounds?
Stop increasing and work even in rounds until the hat reaches its full height — roughly the crown diameter plus 2 to 2.5 inches for a classic beanie. The final stitch count from the table is your body stitch count.