''pi'' hat questions

Hi.:grinning:Does a person have to go by something called pi for making a hat?:cry:What do you guys?:face_with_raised_eyebrow:Any different opinons would be nice.:smiley:

Do you actually mean pi the math thing, π x radius squared?
No, you need to wrap a tape measure around your head and multiply the inches by your stitches per inch.

I think to figure out decreases would be calculus. But don’t make it harder than it has to be, knit fabric is forgiving. You can just bunch up the whole top if you want and it will look fine.
Or use a hat decrease calculator.


Hi Mike.Thanks for your help .I think someone said on the internet that pi is this-
pi (pronounced like pie) is a Greek letter that is used to represent a number that defines circle and sphere geometry–rounded off, pi is 3.14.
So i dont have to go by that?.

Pi would be if you knew the radius or diameter of your head but it was too big to measure the circumference. Your head would need to be a perfect circle.
It would be easier to measure the circumference because it is unlikely your head is larger than 25".

Knitting is forgiving enough that you don’t even need to be that exact depending on what stitch pattern you’re knitting. The yarn council has standards in sizes you could go by and probably be right in most cases.

Building a house with my brother and they pulled out their calculators for rafters I pointed out we could run a tape measure easier. After they mathed wrong and cut boards wrong we ran a tape measure.


I’m not sure what you mean… why would you have to go by pi? I don’t think there’d be many hats knit if that were the case…

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Pi is 3.14 but it has a lot more numbers after the decimal. None of the numbers repeat after the decimal point. We mathematicians use the 3.14 version unless we need more due to our calculations which we are doing. The equation of the circle is circumference of a circle is c=pi time the radius squared.

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Actually, as my math teacher used to say, that’s the formula for the area of a circle.
The circumference is π x diameter (C = πd).

As Mike and Jan said, you don’t need to know the diameter or pi to make a hat, Just measure around the head (circumference) and subtract about an inch for a snug fit.


Before I confuse some people , let me correct and equation. Area is pi r squared. Circumference is 2pir or pid.

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Pie chart important for knitting a hat. :grinning:


I’d say a critical step before knitting anything!

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