New Zealand is approximately 268,838 sq km, while United Kingdom is approximately 243,610 sq km, making United Kingdom 90.62% the size of New Zealand. Meanwhile, the population of New Zealand is ~4.9 million people (60.8 million more people live in United Kingdom).
This to-scale map shows a size comparison of New Zealand compared to United Kingdom. For more details, see an in-depth quality of life comparison of United Kingdom vs. New Zealand using our country comparison tool.