Loggerhead turtles are the most abundant of all the marine turtle species in U.S. waters. But persistent population declines due to pollution, shrimp trawling, and development in their nesting areas, among other factors, have kept this wide-ranging seagoer on the threatened species list since 1978. The turtle occurs throughout the temperate and tropical regions of the Atlantic, Pacific, and Indian Oceans. However, the majority of loggerhead nesting is at the western rims of the Atlantic and Indian oceans. Total estimated nesting in the U.S. is approximately 68,000 to 90,000 nests/year.
I'd say about 120,000. The first article from the US Fish and Wildlife service says that there are about 120,000 nesting sites from the large areas (North Florida through North Carolina (U.S.), Cape Verde Islands (Cape Verde, eastern Atlantic off Africa), and Western Australia (Australia)) with many other nesting sites with only 100-999 nests (Northwest Florida (U.S.), Cay Sal Bank (Bahamas), Quintana Roo and Yucatán (Mexico), Sergipe and Northern Bahia (Brazil), Southern Bahia to Rio de Janerio (Brazil), Tongaland (South Africa), Mozambique, Arabian Sea Coast (Oman), Halaniyat Islands (Oman), Cyprus, Peloponnesus (Greece), Island of Zakynthos (Greece), Turkey, and Queensland (Australia)).
The second article from the National Oceanic and Atmospheric Administration says that the number of nests laid are the best way scientists have to estimate the number of turtles out there (page 3).