Thailand is approximately 513,120 sq km, while Swaziland is approximately 17,364 sq km, making Swaziland 3.38% the size of Thailand. Meanwhile, the population of Thailand is ~69.0 million people (67.9 million fewer people live in Swaziland).
This to-scale map shows a size comparison of Thailand compared to Swaziland. For more details, see an in-depth quality of life comparison of Swaziland vs. Thailand using our country comparison tool.