Belgium is about 13 times smaller than Zimbabwe.

Zimbabwe is approximately 390,757 sq km, while Belgium is approximately 30,528 sq km, making Belgium 7.81% the size of Zimbabwe. Meanwhile, the population of Zimbabwe is ~15.1 million people (3.3 million fewer people live in Belgium).
Tip: This to-scale comparison of Zimbabwe vs. Belgium uses the Mercator projection, which distorts the size of regions near the poles.