NH 11 begins on the western bank of the Connecticut River, where VT 11 crosses from Springfield, Vermont, into Charlestown, New Hampshire, just feet from its intersection with US 5.

NH 12A, a western bypass of downtown Claremont, splits off just south of the city line.

The two highways cross the Sugar River and meet the southern terminus of NH 120 before continuing east towards Newport.

The two routes continue east for another 3.2 miles (5.1 km) before NH 103 splits off to the southeast.

Continuing east into Andover, the highway meets the southern terminus of NH 4A then joins US 4 for 2.7 miles (4.3 km).

In the center of Tilton, the road intersects with NH 132 just feet north of the Northfield town line.

Continuing northeast, US 3 and NH 11 cross Lake Winnisquam and skirt the northern tip of Belmont.

The highway turns southeast along the southern end of the lake and crosses into the town of Alton.

US 202 and NH 11 continue through the district of East Rochester before crossing the Salmon Falls River into Lebanon, Maine.

US 202 continues across the border while NH 11 becomes Maine State Route 11, which is signed as a north-south highway.

New Hampshire Route 11C is a short north–south state highway running for 1.734 miles (2.791 km) entirely in the town of Gilford.

New Hampshire Route 11D was a short state highway running for 3.29 miles (5.29 km) entirely in the town of Alton.