Ireland is approximately 70,273 sq km, while Brunei is approximately 5,765 sq km, making Brunei 8.2% the size of Ireland. Meanwhile, the population of Ireland is ~5.2 million people (4.7 million fewer people live in Brunei).
This to-scale map shows a size comparison of Ireland compared to Brunei. For more details, see an in-depth quality of life comparison of Brunei vs. Ireland using our country comparison tool.