Saint Vincent and the Grenadines is about 1.4 times smaller than Guam.

Guam is approximately 544 sq km, while Saint Vincent and the Grenadines is approximately 389 sq km, making Saint Vincent and the Grenadines 71.51% the size of Guam. Meanwhile, the population of Guam is ~169,086 people (68,117 fewer people live in Saint Vincent and the Grenadines).
Tip: This to-scale comparison of Guam vs. Saint Vincent and the Grenadines uses the Mercator projection, which distorts the size of regions near the poles.