How big will my skein be? (aka "niddy math")

Take the length of the niddy. The yarn goes around it on 4 'sides'. So, the length of one full wrap is 4 TIMES the length of the niddy.

So, my 1.5 foot niddy is a 2-yard wrap (6 feet)
My 9 inch niddy is a 1-yard wrap (3 feet)
A 1 foot niddy would be a 4-foot wrap (1.333 yd)
A 2 foot niddy would be an 8-foot wrap (2.666 yd)

Take the # wraps * the # yards/wrap or, if it's not even, take the # wraps * the # feet/wrap and divide by 3 (3 feet per yard).

You want metric? ask someone with a math degree <vbg>

(posted by me on spindlers, 12/8/2001)

Caveats: someone wise wrote, all instruction is false. And he's right -- we teach what it is handy to teach, leaving out all the screaming details that would bore you so much you'd never learn to spin. So the fine print ... wrapping a niddy is not the most exact way to measure skein length. Consider you are wrapping at an angle to that arm you measured, and sometimes you wrap tightly, sometimes loosely; some yarn is closer in, yadayada. So the count of wraps * 4 * the niddy length is most likely an underestimate, but "close enough for horseshoes". If you want a more exact measure -- use a skein-winder or a McMorran Balance. (Google either term to see what they are)

p.p.s. sometimes topics come up more than once!