Fort Lauderdale is about 3,680 times smaller than Vietnam.

Vietnam is approximately 331,210 sq km, while Fort Lauderdale (excluding the city's 9.9 sq km of water area) is approximately 90 sq km, making Fort Lauderdale 0.03% the size of Vietnam.
Tip: This to-scale comparison of Vietnam vs. Fort Lauderdale uses the Mercator projection, which distorts the size of regions near the poles.