What is the size of coastline?

Coastlines are complex and ever-changing features, and their precise length is difficult to determine. Various factors, such as the scale and method of measurement, can influence the reported length. Additionally, the coastline of a particular region can vary over time due to erosion, accretion, and other coastal processes.

Here are some general approximations of the world's coastline lengths, based on different sources:

1. World Factbook (CIA):

- Total World Coastline Length: Approximately 193,500 miles (311,400 kilometers)

2. National Oceanic and Atmospheric Administration (NOAA):

- Total World Coastline Length: Estimated to be around 246,000 miles (396,000 kilometers)

3. Encyclopaedia Britannica:

- Total World Coastline Length: Approximately 240,000 miles (386,000 kilometers)

4. The Guinness Book of World Records:

- Longest Coastline in the World: Canada, with approximately 151,019 miles (243,000 kilometers) of coastline

5. The World Bank:

- Total World Coastline Length: Estimated to be around 164,000 miles (264,000 kilometers)

It's important to note that these numbers are approximations and may vary depending on the specific methodologies and reference points used. Additionally, due to the dynamic nature of coastlines, the actual lengths may change over time.