There are a few reasons why your legs might not be tanning as much as the rest of your body. It could be that you’re spending more time in the sun on your upper body than your lower body, or that you’re wearing sunscreen or clothing on your legs more often. It could also be down to the fact that melanin is produced in response to UV radiation, and the hair on your legs is thicker than elsewhere on your body, so it takes longer for the melanin to reach the surface. Many tanning salons offer leg tanners which can help. Even regular sunbeds can help ensure you’re getting an even tan across your body.