The national average price to change a roof is $7,211 with the majority of home owners spending between $4,707 and $10,460. Roofing installment price varies from $4 to $5.50 per square foot depending on the roofing size as well as materials utilized in re-roofing. Expect to invest $1,500 to $3,000 to remove your present roofing before setting up a substitute.