Please note that these sizes are pulled from the The Crochet Crowd website (a very valuable source for patterns, information, etc).
Crochet Afghan Sizes
(Information extracted from The Crochet Crowd website: http://thecrochetcrowd.com/afghan-sizes/ )
Kid Sizes
Receiving Blanket – Usually Square starting at 24″ to 36″
Small Cradle – 15″ x 30″
Large Cradle – 18″ x 33″
Baby Blankets Typically Range – Minimum 24″ – 30″ width
Toddler Afghans – Minimum Range from 30″ – 36″ width
Young Child – Minimum Range from 42″ – 48″ width
Teenagers – Minimum 48″ – 60″ width
Other Afghans for Decor
Throw Afghans – 60″ width – 48″ to 60″ length
Lapghan – 36″ width – 48″
Mattress Top Sizes without Drape
Twin – 39″ x 75″
Full / Double – 54″ x 75″
Queen – 60″ x 80″
King – 76″ x 80″
California King – 72″ x 84″
Mattress Sizes with Drape Over Sides
Twin – 69″ x 90″
Full / Double – 84″ x 90″
Queen – 90″ x 95″
King – 106″ x 95″
California King – 102″ x 99″