Standard Stop Sign Dimensions: Size Requirements in the US, UK, Australia & Canada

Published January 15, 2025 · By redstopsign.com editorial team

A stop sign’s size is not arbitrary — it is prescribed by law in every country that uses them. Getting the size wrong on a public road is a traffic safety violation. This guide covers the official dimensional specifications for stop signs in the United States, United Kingdom, Australia, and Canada.

United States — MUTCD Specifications

The Manual on Uniform Traffic Control Devices (MUTCD), published by the Federal Highway Administration, is the authoritative source for US stop sign requirements.

Section 2B.04 of the MUTCD specifies the following minimum sizes:

Road typeMinimum size
Two-lane road, local street30 inches (762 mm)
Multi-lane road, collector, arterial36 inches (914 mm)
Expressway, freeway48 inches (1,219 mm)

“Size” refers to the distance across the sign face from flat side to opposite flat side (not corner to corner).

US sign proportions

A standard US stop sign is a regular octagon — all eight sides are equal length. For a 30-inch sign:

  • Each side: approximately 12.4 inches (315 mm)
  • Inscription height: minimum 10 inches for the word “STOP”
  • White border width: 0.75 inches (20 mm)
  • Red retroreflective sheeting: Diamond Grade or Engineer Grade acceptable

The word “STOP” is set in Series E(M) Highway Gothic, part of the FHWA Standard Alphabets for Highway Signs.


United Kingdom — TSRGD Specifications

In the UK, stop signs are governed by the Traffic Signs Regulations and General Directions 2016 (TSRGD 2016), published by the Department for Transport.

The UK stop sign (Sign CD2 in TSRGD) differs from the US design in several ways:

PropertyUK spec
ShapeRegular octagon
ColourRed (BS 381C shade 537)
Text”STOP” — Transport typeface
Standard size450 mm across flats
Large size (on faster roads)750 mm across flats

UK stop signs are relatively rare. Most UK junctions use give way (yield) lines instead. The stop sign is only used where visibility is seriously restricted.


Australia — AS 1742 Specifications

Australian stop sign standards are set by AS 1742.2 Manual of Uniform Traffic Control Devices — Traffic control devices for general use, published by Standards Australia, and implemented via each state’s road rules.

Road typeSign size
Local / minor road450 mm across flats
Arterial road600 mm across flats
High-speed road750 mm or larger

The Australian sign uses a similar octagonal shape and red/white colour scheme to the US sign, but the proportions and typeface (ARRB-developed font) differ slightly.


Canada — TAC Manual Specifications

Canada’s stop sign dimensions follow the Traffic Control Devices: Manual (TAC), which is closely aligned with the US MUTCD:

Road typeMinimum size
Local / residential600 mm (≈24 inches) across flats
Collector / arterial750 mm (≈30 inches) across flats
High-speed / rural900 mm (≈36 inches) across flats

Canadian signs are bilingual in Quebec — the word “STOP” remains on all Canadian stop signs (the French word arrêt is typically placed below on an additional panel, not replacing STOP).


Quick reference: stop sign sizes by country

CountryStandard sizeLarge size
USA30 inches (762 mm)36–48 inches
UK450 mm750 mm
Australia450 mm750 mm
Canada600 mm750–900 mm

Download stop sign files at correct dimensions

If you need a stop sign file for design or print purposes, our downloads are built to MUTCD proportions: