The product is great for a medium sized toilet don’t recommend for a small or large. (Pics for more reference). Sea sit for heated seat is nice and works well doesn’t eat too much electricity (unsure how long it’ll last until it breaks one day). The width from side to side is about 15 inches

For length it goes from the edge of inner toilet to top of toilet (pic for reference) is about 16 inches long (length) wise.