Yarn Calculator
This is a rough planning range based on Lion Brand’s published yardage chart for common projects and yarn-weight classes.
Formula and sources updated · Data sources · 1View algorithm, constants and default inputs (JSON)
About this calculator
This rough yardage range is looked up by project type and yarn-weight class from Lion Brand’s published chart, then adjusted by your waste allowance. Pattern, size, gauge and stitch can change the amount substantially; follow the pattern or a swatch when available. Skeins are rounded up using the high end of the adjusted range. Price uses the same currency you enter; no conversion is done.
Worked example
calculated with the default values below
Project type Adult sweater · Yarn weight class Yarn weight 4 · Yards per skein 200 yards · Price per skein (your currency) 6 · Waste allowance 15 % Estimated low yardage 1,294 yards · Estimated high yardage 1,869 yards · Midpoint yardage estimate 1,581 yards · Midpoint yardage estimate 1,446 m · Skeins to buy (based on high estimate) 10 · Estimated yarn cost (same currency) 60.00
Data sources
Disclaimer
These calculators provide planning estimates only. Building codes, wiring regulations and safety requirements differ by country and change over time, and nothing here replaces a licensed professional or a permit. For structural, electrical or gas work, follow local code and have the installation inspected.
Implementation source
This record describes the implementation used by this page. It is not independent validation. External references, when available, support only the stated formula or definition; estimates and custom rules retain their own assumptions.
Formula and variables
L_low_adj = L_low×(1+p/100); L_high_adj = L_high×(1+p/100); L_mid = round((L_low_adj+L_high_adj)/2); skeins = ceil(L_high_adj/s); cost = skeins×c
- type
- Project type and yarn-weight class lookup
- L_low
- Low chart yardage
- L_high
- High chart yardage
- p
- Waste allowance (%)
- s
- Yards per skein
- c
- Price per skein
Look up the low/high yardage by project and yarn-weight class, then multiply both bounds by (1 + waste%). The displayed yards are the rounded midpoint; meters = midpoint×0.9144; skeins = ceil(adjusted high ÷ yards per skein); cost = skeins×entered price. Ranges are estimates from [Lion Brand’s published chart](https://blog.lionbrand.com/wp-content/uploads/2019/03/HowMuchYarn_021819_H.pdf).
Frequently asked questions
Why were the scarf and sock yardage ranges changed?
The published chart lists separate ranges by project and yarn-weight class. The previous lookup had the scarf and sock rows swapped. For example, a weight-1 scarf is listed at 525–825 yd while weight-1 socks are 350–500 yd. The calculator now uses the chart rows and applies waste to both endpoints, then rounds skeins up from the high endpoint. [Lion Brand chart](https://blog.lionbrand.com/wp-content/uploads/2019/03/HowMuchYarn_021819_H.pdf).