There are a number of factors that go into determining the cost of carpet padding. While the padding itself costs $3 to $4 per square yard, that figure doesn't factor in the cost of materials and labor. Installers generally charge a minimum of $3 per square yard for installation, but the price can rise to $6 or more per square yard for larger rooms and spaces. If the homeowner wants to install carpet in an unusually shaped room, the price will also rise.