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

Saint Vincent and the Grenadines is approximately 389 sq km, while Sydney is approximately 27 sq km, making Sydney 6.86% the size of Saint Vincent and the Grenadines.
Tip: This to-scale comparison of Saint Vincent and the Grenadines vs. Sydney uses the Mercator projection, which distorts the size of regions near the poles.