Saint Vincent and the Grenadines is about 2.2 times smaller than San Diego.

San Diego is approximately 844 sq km, while Saint Vincent and the Grenadines is approximately 389 sq km, making Saint Vincent and the Grenadines 46.09% the size of San Diego.
Tip: This to-scale comparison of San Diego vs. Saint Vincent and the Grenadines uses the Mercator projection, which distorts the size of regions near the poles.