If you know your quilt will be used on a specific bed, then it’s best to measure the bed and calculate the correct size for the quilt. That way you can take into account the thickness of the mattress and how far down the side of the bed you want the quilt to hang (the “drop”).
Quilting Contessa, of Quilting Hub, provides excellent instructions for determining the quilt size based on a specific bed. They’re clear and take into account every important measurement.
Image from “Turn Flat Sheets Into Fitted Sheets in 6 Easy Steps.”
But, what if the quilt is a gift and you don’t know what bed it will be used on? In that case, make the quilt a standard quilt size, say a twin or a queen. The recipient will be thrilled and will use the quilt wherever they want.
Photo Credit: Tiny Bed with Quilt (and pillows) by Artsy Lady.