A Good Yarn ... All About YPOs, YPPs and WPIs

Yarn Gauge – How Many Yards Per Ounce or Pound, and How Many Wraps Per Inch?

There are a lot of ways to measure the thickness of yarn. YPO is “yards per ounce.” YPP is “yards per pound.” WPI is “wraps per inch.” To calculate WPI, you wrap your yarn around a ruler or a pencil so the strands are just touching, and count how many wraps you can make per inch. For bulky yarns, it is best to wrap your yarn for three inches then divide the number of wraps by three. Following are some rough YPO, YPP and WPI guidelines for different sizes of yarn.

Sock weight
YPO = 175+ yards
YPP = 2400+ yards
WPI = 16 – 18+ wraps

Fingering (super fine, sock, baby) weight
YPO = 100 – 150 yards
YPP = 1600 – 2400 yards
WPI = 16 wraps

Sport (fine, DK) weight
YPO = 75 – 100 yards
YPP = 1200 – 1600 yards
WPI = 14 wraps

Medium (worsted) weight
YPO = 55 – 70 yards
YPP = 850 – 1100 yards
WPI = 12 wraps

Bulky (chunky) weight
YPO = 30 – 55 yards
YPP = 500 – 850 yards
WPI = 10 wraps

Super bulky (extra bulky or “chunky”) weight
YPO = 16 – 30 yards
YPP = < 500 yards
WPI = 8 or fewer wraps