Guinea is approximately 245,857 sq km, while Tajikistan is approximately 144,100 sq km, making Tajikistan 58.61% the size of Guinea. Meanwhile, the population of Guinea is ~12.4 million people (3.9 million fewer people live in Tajikistan).
This to-scale map shows a size comparison of Guinea compared to Tajikistan. For more details, see an in-depth quality of life comparison of Tajikistan vs. Guinea using our country comparison tool.