Saint Vincent and the Grenadines is about 1.9 times smaller than Dominica.

Dominica is approximately 751 sq km, while Saint Vincent and the Grenadines is approximately 389 sq km, making Saint Vincent and the Grenadines 51.8% the size of Dominica. Meanwhile, the population of Dominica is ~74,629 people (26,340 more people live in Saint Vincent and the Grenadines).
Tip: This to-scale comparison of Dominica vs. Saint Vincent and the Grenadines uses the Mercator projection, which distorts the size of regions near the poles.