Thailand is approximately 513,120 sq km, while Belgium is approximately 30,528 sq km, making Belgium 5.95% the size of Thailand. Meanwhile, the population of Thailand is ~69.0 million people (57.3 million fewer people live in Belgium).
This to-scale map shows a size comparison of Thailand compared to Belgium. For more details, see an in-depth quality of life comparison of Belgium vs. Thailand using our country comparison tool.