Guinea is approximately 245,857 sq km, while Pitcairn Islands is approximately 47 sq km, making Pitcairn Islands 0.02% the size of Guinea. Meanwhile, the population of Guinea is ~12.4 million people (12.4 million fewer people live in Pitcairn Islands).
This to-scale map shows a size comparison of Guinea compared to Pitcairn Islands. For more details, see an in-depth quality of life comparison of Pitcairn Islands vs. Guinea using our country comparison tool.