Spinning Wheel Ratio Calculator

Question 1

How do I calculate my spinning wheel’s drive ratio?

Accepted Answer

Measure the diameter of your drive wheel and the diameter of the whorl (pulley). Divide the drive wheel diameter by the whorl diameter. For example, a 22-inch wheel with a 2.5-inch whorl = 8.8:1 ratio.

Question 2

What ratio do I need for sock yarn?

Accepted Answer

Sock yarn (fingering weight) typically requires a ratio of 8:1 to 14:1 to get enough twist for durability. Higher ratios add more twist per treadle, which is what you want for strong, thin singles.

Question 3

What is TPI in spinning?

Accepted Answer

TPI stands for Twists Per Inch. It measures how many times the fiber twists in one inch of yarn. More TPI = stronger, harder yarn. Less TPI = softer, loftier yarn.

Question 4

How much plying twist do I need?

Accepted Answer

For balanced 2-ply yarn, ply at roughly 60% of your singles TPI in the opposite direction. Our calculator gives you the exact plying twist based on your singles TPI and number of plies.

Question 5

What does scotch tension mean?

Accepted Answer

Scotch tension is a braking system where a band applies friction to the bobbin. The drive band turns the flyer, and the scotch tension controls how fast the yarn winds on. It’s the most common system for beginners.

Question 6

How do I choose the right whorl?

Accepted Answer

Smaller whorls = higher ratio = more twist = thinner yarn. Larger whorls = lower ratio = less twist = thicker yarn. Our reference chart matches whorl ratios to target yarn weights.

Yarn Weight	Ratio Range	WPI	TPI Range
Lace (0)	12–20:1	18–30	8–14
Fingering (1)	8–14:1	14–18	5–10
Sport (2)	6–10:1	12–14	4–8
DK (3)	5–8:1	10–12	3–6
Worsted (4)	4–7:1	8–10	3–5
Bulky (5)	3–5:1	5–8	2–4
Super Bulky (6)	2–4:1	3–5	1–3

Spinning Wheel Ratio Calculator

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