Floating vanities come in several sizes and heights. Typically, people will find heights ranging from 18 inches high to 20 inches high, although they are installed so that they reach the total average vanity height of 30-32 inches. You can also have them installed at a custom height.
Like all furniture, these vanities will also have a weight limit to consider. This will vary from one model to the next, depending on things like materials, installation or anchor style, and other factors. Typically, the average 150-200 pound floating vanity can be installed securely without incident.