Contact the operator
This address is for Swatch Ledger feedback, corrections and editorial enquiries. We do not offer individual textile testing or garment-care advice.
For a calculation issue
Please include which calculator you used, the units, your input numbers and the result you expected. A browser name is helpful if a button did not work. Do not send passwords, financial details or personal documents.
For educators and editors
You are welcome to link to the calculator or a worked example. Please describe its limits accurately: it compares supplied measurements and assumes the measured rate repeats when planning length. It is not a fibre-specific predictor or a certified shrinkage test.
Linking to a source on this website does not imply a partnership, endorsement or completed professional review. If you can help identify a material error, please send the details.