Which loom, how many pegs, how many rows — instantly
Tap a size to auto-fill, or enter an exact measurement below
Loom knitting gauges vary — these defaults are good starting approximations. Swatch to confirm!
Pick a size or enter a head measurement to see your plan
A round loom has a fixed peg count, and on a loom the pegs are the stitches. So the finished circumference of the hat is simply pegs ÷ stitches per inch, and choosing a loom means choosing which of 24, 31, 36 and 41 pegs lands closest to the head you are knitting for — once you have taken the stretch into account.
Negative ease is the whole trick. A hat that measures the same as the head falls off. The calculator works out the actual finished circumference of every standard loom at your gauge, keeps only the ones landing between 4% and 20% negative ease, and picks the one closest to a 15% target. If nothing lands in that band it says so and gives you the exact peg count an adjustable loom would need — it will not talk you into a hat that does not fit.
Rows come from height, not pegs. Rows = target hat height × rows per inch, and rows per inch defaults to 1.5 × your stitch gauge in e-wrap (1.6 × in u-stitch). A folded brim adds about 2 inches of extra rows.
An adult medium, 22" head, two strands of worsted held together, e-wrap — 2.0 sts/inch and 3.0 rows/inch:
That reproduces the classic loom-chart rule — adult equals the 36-peg loom — from the maths rather than from a table, which is why it still works when you switch to super bulky or u-stitch.
For the full peg-count-to-circumference table see the loom peg chart, and for head circumference by age see the printable hat size chart. Once you know the loom, the loom knitting pattern generator writes the whole pattern with stripes.
The classic 4-loom set (peg counts & diameters are the common Boye / Knifty Knitter–style sizes — approximate)
| Loom | Pegs | Diameter | Typical Hat Size |
|---|---|---|---|
| Small | 24 | ~5.5" | Preemie & newborn |
| Medium | 31 | ~7.5" | Baby 6–12 mo & toddler |
| Large | 36 | ~9.5" | Child, teen & most adults |
| Extra Large | 41 | ~11.5" | Large adult & slouchy styles |
The questions every loom knitter asks
A 36-peg round loom, about 9.5" across, for a fitted adult hat on a 21–23" head knitted with two strands of worsted in e-wrap. Go up to the 41-peg loom (~11.5") for a large adult head or a slouchy fit. At 2 sts/inch a 36-peg loom finishes about 18" around, which is 18% smaller than a 22" head and stretches to fit.
The 24-peg loom for preemie and newborn heads of about 12–14", and the 31-peg loom for babies from six months through toddler, roughly 17–19". Those are the two smallest looms in the classic four-loom round set.
Yes — aim for a finished circumference about 8–10% smaller than the head so the hat stretches to fit snugly. This calculator builds the ease in for you.
Knit to the target hat height — roughly 5" for a newborn, 6.5" for a toddler and 8–8.5" for an adult — then gather. On a large-gauge loom at about 3 rows/inch an adult hat is around 24 rows. Add about 2", or 6 more rows, for a folded brim.
E-wrap is stretchier and faster, and is the default for hats. U-stitch is denser and runs about 10–15% more stitches per inch, so it knits up slightly smaller on the same loom. The calculator adjusts the gauge for you.