On-line retailers that offer linens and bedding, such as Cuddledown.com, often include a reference chart with standard dimensions for duvet or comforter covers. Other sources are do-it-yourself sites such as Buyfabrics.com or Wescofabrics.com, which offer charts to calculate yardage requirements.
Sizes for comforters and blankets can vary by manufacturer. Anyone shopping for a duvet cover should measure the comforter to be certain that the duvet cover fits. The most common sizes for beds and linens in the United States are twin, full, queen and king. Non-standard sizes, including college twin or California king, are also available. Calculators help estimate the yardage to sew a duvet and may include links with sewing instructions.