Last updated: October 2026
These Terms of Use govern your use of fibermath.com (the “Site”). By using the Site you agree to these terms. If you do not agree, please do not use the Site.
What the Site provides
FiberMath offers free online calculators and reference content for knitting, crochet and quilting, such as yarn yardage estimates for blankets and fabric, binding and batting calculations for quilts. The Site is free to use and does not require an account.
Estimates, not guarantees
All results are estimates based on the assumptions stated next to each calculator: typical yardage from published patterns, standard fabric widths, seam allowances and margins. Your actual needs depend on your pattern, gauge, stitch, tension, fabric shrinkage and cutting. Always check your pattern and consider buying a little extra, ideally from the same dye lot. We are not responsible for any shortfall, excess purchase or other loss arising from the use of these results.
Data sources
Yarn estimates are derived from aggregated statistics of publicly listed blanket patterns on Ravelry. FiberMath is not affiliated with or endorsed by Ravelry or any yarn or fabric brand mentioned on the Site. Brand and product names belong to their respective owners.
Acceptable use
You may use the calculators for personal and commercial craft projects. You may not copy the Site’s content or code in bulk, scrape it automatically, attempt to disrupt the Site, or use it for any unlawful purpose.
Intellectual property
The text, calculators, design and code of the Site are owned by FiberMath unless stated otherwise. You may quote short extracts and link to any page, with attribution.
Advertising and affiliate links
The Site may display advertising and may contain affiliate links to retailers. If you buy through an affiliate link we may earn a commission at no extra cost to you. This never changes the results of our calculators.
Third-party links
The Site may link to external websites. We do not control and are not responsible for their content or practices.
Disclaimer of warranties
The Site is provided “as is” and “as available”, without warranties of any kind. We do not guarantee that it will be error-free or always available.
Changes
We may update these terms at any time. The date at the top of this page shows when they were last changed.
Contact
Questions about these terms: [email protected].