Spain is approximately 505,370 sq km, while New Caledonia is approximately 18,575 sq km, making New Caledonia 3.68% the size of Spain. Meanwhile, the population of Spain is ~50.0 million people (49.7 million fewer people live in New Caledonia).
This to-scale map shows a size comparison of Spain compared to New Caledonia. For more details, see an in-depth quality of life comparison of New Caledonia vs. Spain using our country comparison tool.