United Kingdom is approximately 243,610 sq km, while Swaziland is approximately 17,364 sq km, making Swaziland 7.13% the size of United Kingdom. Meanwhile, the population of United Kingdom is ~65.8 million people (64.7 million fewer people live in Swaziland).
This to-scale map shows a size comparison of United Kingdom compared to Swaziland. For more details, see an in-depth quality of life comparison of Swaziland vs. United Kingdom using our country comparison tool.