Rigid Heddle Loom Warp & Weft Calculator - Kelly Casanova Weaving Lessons

Planning your weaving projects just got easier! This free Warp & Weft Calculator takes the guesswork out of determining how much yarn you need for your rigid heddle loom. Simply enter your project dimensions, sett, and other simple weaving details, and the calculator will automatically determine your warp and weft yardage.

No more running out of yarn mid-project or buying too much—get precise calculations for warp length, weft requirements, and shrinkage allowance all in one place. Try it out below!

If you prefer the old school method of pen and paper, I have you covered for that too! Check out my free printable calculations sheet that also includes a mini class to walk you through filling out the calculations!

Please note, the calculator is not perfect, for example, the weft section at the bottom does overestimate slightly. Hopefully I can fine-tune that!

Warp Calculation Quiz

Calculate Your Warp & Weft Requirements

Width Calculation

Desired width (off loom) (inches): Shrinkage allowance (10%): Total width (inches): Sett (ends per inch): Total ends:

Length Calculation

Desired length of project (inches): Shrinkage allowance (10%): Number of items: Length of each item (inches): Gap allowance (inches): Fringe allowance (inches): Sampling (inches): Waste allowance (18 inches): Total warp length (inches): Total warp length (yards):

Yarn Requirements

Yarn Required for Warp

Warp ends: Multiplied by total length in yards: Total warp yarn needed (yards): Total warp yarn needed (metres):

Yarn Required for Weft

Total width (inches): Shrinkage allowance (10%): Multiply by picks per inch (PPI): Multiply by total length of weaving (inches): Divide by 36: Total weft required (yards):

Need some help to understand and use the calculator? Check out this free tutorial to get you started:

I hope this calculator is super helpful and helps you get started on your weaving project quickly and easily!

Until next time…

Happy Weaving!

Comments

Lili

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I’m confused if I need the same amount of ends or not on my warp to weave twill than if I were weaving tabby. I can’t find the information anywhere. Thanks.

- Kelly
  
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  I just answered this for you over at your comment on the weaving school 😉
  
Nancy

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You allowed for shrinkage in with width and length calculations. However, you also allowed for shrinkage in the yarn required for the weft. Isn’t this duplicating what was done for the width calculation? And you didn’t allow shrinkage for the warp? I’m a bit puzzled.

- Kelly
  
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  I admit it’s a work in progress Nancy, coding is not my particular talent and it took me hours to fine-tune it to this point. But I will try to go back and fix any inconsistencies when I can 😊
  
Annabelle Johnstone

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Where is the metric version???!!!

- Kelly
  
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  I’m sorry, I only have the imperial version.
  
Tammi

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Thank you so much for this tool! I’m a pre-weaver (waiting for loom to arrive) and was really lost trying to figure out how much yarn was needed for a project. I’ve watched dozens of your videos on UouTibe and they’re so helpful.

- Kelly
  
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  That’s great to hear Tammi, thank you! And congrats on the new loom, which one did you decide on? 😀
  
Jennifer Puett

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I bought 2 hardback notebooks to weave covers for. I will try this out since I know the definite dimensions needed. Thanks!

- Kelly
  
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  Great, I hope they turn out well 😊