Structural Engineer Costs. Homeowners spend an average of $512 on hiring a structural engineer, with most homeowners spending between $319 and $708. The larger and more detailed the project is, the higher the cost of hiring a structural engineer becomes. Some professionals charge by the job, while others may charge by the hour.
The total surface area of Earth is about 197 million square miles (509 million square km). About 71 percent is covered by water and 29 percent by land.
Boundaries of China superimposed upon those of the USA. Let's do the math again, but this time for the entire planet. The total land surface area of Earth is about 57,308,738 square miles, of which about 33% is desert and about 24% is mountainous. Subtracting this uninhabitable 57% (32,665,981 mi2) from the total land area leaves 24,642,757 square miles or 15.77 billion acres of habitable land.