Are the toe socks sized (on the chart) by shoe size or by sock size? For instance, I wear a size 8 shoe - what size sock would I buy?Thank you.

Tech Specs:

Material:

70% CoolMax, 25% lycra, 5% spandex 

Height:

below the ankle 

Recommended Use:

trail running, hiking, casual wear 

Manufacturer Warranty:

1 year