The cost to install backsplash averages $23.52 – $40.28 per square foot based on data 2014 from homewyse.com.The cost divides into three subjects such as average material costs, unit labor productivity rates and also national average hourly labor wages.he cost to install backsplash averages $23.52 – $40.28 per square foot based on data 2014 from homewyse.com.