Solomon Islands is about 43 times smaller than Mali.

Mali is approximately 1,240,192 sq km, while Solomon Islands is approximately 28,896 sq km, making Solomon Islands 2.33% the size of Mali. Meanwhile, the population of Mali is ~20.7 million people (20.0 million fewer people live in Solomon Islands).
Tip: This to-scale comparison of Mali vs. Solomon Islands uses the Mercator projection, which distorts the size of regions near the poles.