GEOGRAPHY & CARTOGRAPHY CALCULATOR
Areaterritorial Waters Area
A precise tool.
What is the Areaterritorial Waters Area & How does it work?
Territorial waters, also known as the territorial sea, extend outward from a nation’s coastline and are subject to the sovereign jurisdiction of that state. The most common legal definition, established by the United Nations Convention on the Law of the Sea, sets this limit at twelve nautical miles (approximately 22.224 km) from the baseline, which is usually the low‑water line along the coast.
Because coastlines are rarely straight, the actual area of a country’s territorial sea is estimated by treating the sea as a uniform buffer that runs parallel to the shore. In this simplified model the area can be approximated by multiplying the total length of the coastline by the width of the territorial sea. More sophisticated calculations may incorporate curvature and islands, but the length‑times‑width approach provides a quick, educational estimate.
The resulting figure is expressed in square kilometres (km²), which allows for easy comparison between nations and supports geographic analyses such as maritime resource allocation, environmental monitoring, and geopolitical studies.
A = L times W
L = coastline length (km), W = territorial sea width (km)
Parameters
Result
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Frequently Asked Questions
What is the standard width of territorial waters?
The standard width of territorial waters is twelve nautical miles from the baseline.
How is the baseline for territorial waters typically defined?
The baseline for territorial waters is usually the low-water line along the coast.
Can a country’s coastline have an irregular shape affect its territorial sea area?
Yes, because coastlines are rarely straight, the actual area of a country’s territorial sea can be larger than expected.
What is the legal basis for defining territorial waters?
The legal basis for defining territorial waters is established by the United Nations Convention on the Law of the Sea.
How do you calculate the area of a country’s territorial sea?
To calculate the area, estimate the coastline length and multiply it by the width of the territorial sea (twelve nautical miles).
Results are for informational purposes only and do not constitute professional advice.