Pi Day Beanie by Lynn Venghaus

Pi Day Beanie

January 2015
Worsted (9 wpi) ?
18 stitches = 4 inches
in stockinette
US 7 - 4.5 mm
65 - 70 yards (59 - 64 m)
Adult Medium and Large 21-22" and 23-24"
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This pattern is available as a free Ravelry download


These Pi Beanies are designed to keep your head warm and add a bit of geek fun in the process. The beanies are also a great stash buster project!

People who love Math will love these!
The stripes are worked in rows that correspond to the digits in Pi (3.1415…) – the formula for calculating the diameter or circumference of a circle. Using this pattern, beanies can be constructed using the initial three rounds above the ribbing (shown here in yellow) to represent the 3, a contrasting stripe (shown in black) to mark the decimal and then working the number of rows for the first eleven digits that follow the decimal point.

Needles: size 7 US (4.5 mm) 16” circular and DPNs or 40” circular for magic loop construction.

The shaping is easy with the help of ring markers.– 1 to mark beginning of round. 10 more for decreasing assistance

GAUGE: 18 st = 4” on size 7 with stockinette stitch

TWO SIZES included: Measure the head just above the ears with a cloth tape. Instructions included for 21-22” as well as 23-24” circumference.

SKILLS NEEDED: Knit, purl, 1x1 ribbing, k2tog, adding a new color, working in the round

The hats are created using worsted weight yarn (level 4). I used Cascade 220 Superwash and Rowan 100% wool superwash. You can use any brand worsted weight yarn but I suggest you use two solid colors and make the round for the decimal in black, white or gold. Yarns that have been test-knitted are listed in the full pattern.

Charts and written instructions are provided with several illustrations. I’ve also included the amount of yarn you’ll need for long-tail cast on and the contrasting decimal stripe. There’s also instructions on how to work in the round without having a ‘jog’ when changing colors and how to ‘carry’ the yarn to avoid having lots of ends to weave in.

Get started right away and make Pi hats for your nerdy friends: math teachers, engineering types, accountants, cookie and pie bakers, people who enjoy puns, kids who get good grades, the list is endless! Work them up in team colors to create Beaver Pi, Bronco Pi, Seahawk Pi, Viking Pi, Cardinal Pi, Wildcat Pi, Packer Pi, etc.

This FREE version includes instructions for the Beanie but there’s another pattern that’s for sale which includes instructions for an 18-1/2” stocking hat (27 digits after the decimal) with a pompom as well as a much longer version -36” and 45 digits after the decimal point! You can find it here on Ravelry as “Pi Day Hats x3” .

Thanks for your interest in my patterns!