U.S. Street and Road Sign Dimensions: Sizes & Heights

A road sign's panel dimensions depend on its message, shape, roadway type and installation. The current FHWA MUTCD 11th Edition with Revision 1 gives tables of minimum and larger sign sizes. These are examples from the MUTCD; state and local adoption and project requirements may also matter.

MUTCD size tables show different dimensions by roadway classification. For conventional roads, a STOP sign is typically listed as 30 × 30 inches for a single-lane road and 36 × 36 inches for a multi-lane road; oversized STOP signs are 48 × 48 inches. A YIELD sign is triangular: 36 × 36 × 36 inches on a single-lane conventional road and 48 × 48 × 48 inches on a multi-lane conventional road. A speed-limit sign is 24 × 30 inches on a single-lane conventional road and 30 × 36 inches on a multi-lane conventional road. Freeway sizes can be larger. See our U.S. stop sign dimensions guide.

The panel for a street-name sign can be longer or shorter depending on the street name; the MUTCD table specifies minimum letter heights, not one fixed plate size. Examples include 6-inch uppercase letters with 4½-inch lowercase letters for many post-mounted signs, and 8-inch/6-inch lettering on multi-lane roads posted above 40 mph. Overhead street-name signs use 12-inch/9-inch letter heights. On some low-speed local streets, smaller 4-inch/3-inch lettering is allowed.

For post-mounted signs at the side of the road, the MUTCD minimum measured from the sign's bottom edge is 5 feet in rural areas. It is 7 feet in business, commercial or residential areas where people walking or parking may be present or where the sign could be blocked. Signs above a sidewalk must also be at least 7 feet above the sidewalk. These are minimum installation heights under the MUTCD; overhead signs and special cases follow different clearances. See FHWA's current MUTCD edition and revision information.