What thickness of yoga mat should I buy?

Most studio practitioners settle on 4–6mm: enough cushion for joints without losing balance in standing poses. Reviewers across r/yoga note that 1-inch (25mm) mats like the Retrospec Solana are great for stretching, Pilates, and sensitive knees, but feel unstable in standing balance work. Hot-yoga practitioners typically prefer 3.5–5mm grip-focused mats.