What is the total length of the US-Mexico border?
Executive summary
The U.S.–Mexico international boundary is most commonly reported as about 1,954 miles (3,145 kilometers) long; that figure appears in multiple government and widely used reference sources [1] [2] [3]. Slight alternative tallies — often shown as 1,951 miles, 1,933 miles, or rounded to 1,954 miles — reflect different measurement choices and definitions used by sources [4] [5] [6].
1. The headline figure: about 1,954 miles (3,145 km)
Authoritative and reference sources repeatedly use the 1,954‑mile (3,145 km) figure as the total continental length of the U.S.–Mexico border, and it is the distance shown on U.S. government maps and the CBP “Smart Wall” map description [1] [3] [2]. Encyclopedia and research‑starter summaries also default to roughly 1,954 miles when describing the boundary that runs from the Pacific Ocean in California to the Gulf of Mexico in Texas [6] [7].
2. Why some sources say 1,951, 1,933 or other numbers
Minor discrepancies — for example the White House archive’s 1,951‑mile figure and Business Insider’s 1,933‑mile reporting — stem from rounding, different baselines for measurement, or whether short maritime segments are counted differently [4] [5]. Historical compendia and older tables from geological agencies and the Census have slightly different tallies depending on the method and era of mapping used [8].
3. Measurement complications: rivers, coastlines and what “border” includes
A principal technical reason measurements vary is the Rio Grande: roughly 1,255 miles of the international boundary follows that river, and measuring a winding river’s course gives a longer distance than a straight‑line map measurement; the remaining ~699 miles are terrestrial segments along land and short coastal arcs [1] [9]. Some counts include small maritime boundaries — the Pacific coast and Gulf approaches — while others focus only on the continental land and river line, producing slight differences [9].
4. What official agencies and mapping projects use
U.S. agencies and mapping efforts tend to standardize on the 1,954‑mile figure: the Department of Transportation graphic and U.S. Customs and Border Protection’s Smart Wall materials both use that length when describing the Southwest border [3] [2]. Advocacy groups and journalists sometimes emphasize alternate figures when highlighting specific policy points (fence miles, unfenced stretches), which is why reporting about “miles of wall” or “miles fenced” will cite different sub‑totals without disputing the overall boundary length [10] [11].
5. Practical takeaway: consensus with caveats
For practical purposes — mapping, policy discussions, and most public reporting — the accepted total length of the U.S.–Mexico border is about 1,954 miles (3,145 km), with small, explainable variations (1,951–1,954 and occasional 1,933 figures) arising from measurement method, rounding, and whether tiny maritime sections are included [1] [4] [5]. Reports that break the border into component figures (for example the Rio Grande portion versus land portions) help explain why fencing or barrier mileage figures are presented separately from the border’s total length [1] [10].