Online calculators can estimate the cost of a screened-in porch based on the size of the porch and the area you are in. Calculators factor in the cost of all materials, labor, equipment and the porch itself. As of 2015, the average cost is estimated at $70 per square foot.
The $70 per square foot estimate does not include any extra features for the porch. Lighting, fans, fireplaces and other structural enhancements can significantly add to the final price of the porch. Professional designs also add to the final cost and are not factored into the online estimators. City fees and taxes also play a role in the final cost.
The materials chosen to build the porch can also be a factor when considering the final price. Using materials that are resistant to scratches, rot and mildew is important. Composite and PVC materials, however, may have a higher price tag than what the online calculators estimate.
General contractor fees can also add to the cost of a screened-in porch. The average cost of a general contractor is between 12.1 and 19.3 percent of the porch price. The contractor supervises the project, which usually takes place over two to three weeks.