For a straightforward installation of a single standard box in an accessible location, homeowners often see $120-$260. Projects involving new or upgraded circuits, larger panels, or difficult access commonly run $800-$1,600, with high-end setups surpassing $3,000 in some. Homeowners typically pay a broad range for electrical box installation, driven by box type, wiring complexity, and local labor rates. Cost and price details focus on realistic estimates. Installing a 100-amp subpanel is usually driven by the need to expand electrical capacity for specific areas, such as a garage, workshop, or home addition. This article breaks down the price so buyers can estimate a realistic.