The cost of professional window installation varies depending on the type of window, materials, and labor involved. On average, homeowners can expect to pay between $300 and $1,200 per window, including installation. Basic single-hung windows tend to be on the lower end of the scale, while custom, energy-efficient, or large-sized windows can push costs higher. Replacing multiple windows in a home can sometimes result in package discounts, so it’s worth discussing with your service provider. Be sure to ask for a detailed quote that breaks down labor and material costs for full transparency.