Vietnam is approximately 331,210 sq km, while New Caledonia is approximately 18,575 sq km, making New Caledonia 5.61% the size of Vietnam. Meanwhile, the population of Vietnam is ~98.7 million people (98.4 million fewer people live in New Caledonia).
This to-scale map shows a size comparison of Vietnam compared to New Caledonia. For more details, see an in-depth quality of life comparison of New Caledonia vs. Vietnam using our country comparison tool.