Mathgirl Hat by Knitting for Sanity

Mathgirl Hat

November 2015
Fingering (14 wpi) ?
28 stitches and 40 rows = 4 inches
in Mathgirl pattern
US 2 - 2.75 mm
US 3 - 3.25 mm
220 - 300 yards (201 - 274 m)
Small & Medium
This pattern is available for $5.00 USD buy it now


This hat was inspired by the hat CASSANDRA wore on the TV Show THE LIBRARIANS in Episode 4, SANTA’S MIDNIGHT RUN.

I hope you enjoy this unique design.*

I used Knit Picks Hawthorne Kettle Dyed in color Wisp and made a second one in Knit Picks Gloss. I used Gloss Lace yarn double stranded, but you can use Gloss Fingering one stranded. The silk content gives the hat a nice shiny/glossy effect.

Finished Size: 17 in circumference, unstretched, fitting up to a 21 in head (18 in circumference, unstretched, fitting up to a 22.5 in head), length 11 in.

Needles: US 2 (2.75 mm) & US 3 (3.25mm), circular needle length 16 in, DPNs or magic loop for decreasing rows.

Notions: markers (m), cable needle, tapestry needle.

Gauge: 28 stitches and 40 rounds = 4 inches in pattern on larger needles.


  • This is a slouchy hat but you can fold over the brim to wear it as a fitted beanie.
  • The pattern comes in 2 sizes. The pattern is very stretchy and adjust to a variety of head sizes.
  • The pattern includes written directions, charts and a photo tutorial for this unique stitch combination.
  • This is an intermediate to advanced knitter project. The included photo tutorial will help the seasoned beginner to work this pattern too.
  • Pattern has been test knitted and tech edited.

A big thank you to my awesome testers and check out their beautiful completed projects.