Generally, retail cost for medium grade wood is between $4 dollars and $6.50 per square foot, however the cost of hardwood flooring and the labor involved depends on both the quality of materials and the area of the country/state you live in.  The full range for all quality levels is $3 to $14 per sq ft. When budgeting you’ll need to add about 10% more flooring than the actual space you are adding your hardwood floor to. Labor is the part which fluctuates most based on your geography. How much contractors charge is something that varies wildly, from $2 per square foot up to around $6 per square foot. It’s recommended that you check with a few contractors in your area to understand the costs before starting your project. Additionally, you can save money on your project by going the DIY route.