From its southern terminus to its northern one, Route 7A spans 25.3 miles (40.7 km).

However, its "signed" sections only add up to approximately 5.6 miles (9.0 km), with the connection made via US 7.

The southern segment begins at the Connecticut border, where the unsigned Connecticut State Road 832 connects Route 7A to its parent route 0.3 miles (0.48 km) south in the town of North Canaan.

Route 7A runs northward for nearly 3 miles (4.8 km) as Ashley Falls Road, passing through the village of Ashley Falls and crossing the Housatonic River before rejoining its parent route in the town of Sheffield.

Route 7A continues northward through Lenox Village along Main Street, ending finally at its parent route approximately 1 mile (1.6 km) northward.