Saint Vincent and the Grenadines is about 15 times smaller than Brunei.

Brunei is approximately 5,765 sq km, while Saint Vincent and the Grenadines is approximately 389 sq km, making Saint Vincent and the Grenadines 6.75% the size of Brunei. Meanwhile, the population of Brunei is ~478,054 people (377,085 fewer people live in Saint Vincent and the Grenadines).
Tip: This to-scale comparison of Brunei vs. Saint Vincent and the Grenadines uses the Mercator projection, which distorts the size of regions near the poles.