The smallest I've done is 45x60, and that was for my...ahem "vertically challenged" grandmother. I don't really like "lap" quilts though...I want a quilt I can roll up in like a burrito, so I tend to do 60x80 average for a snuggle/throw quilt as a gift, and even bigger for myself. lol I base the size largely on who will be getting it and make it bigger or smaller depending on their body size.