Knowing exactly how wide and tall you want the accent chair will allow you to determine the placement, as it will give you a rough idea of how much space you need to work with. It will also help you decide on a style later down the line, as some styles are better suited to large or smaller sizes.
The average floor to seat height falls in the range of 30” to 40” but may reach up to 50” for taller people.
For a chair with armrests, the arm height is usually about 10” inches less than the floor to seat height to ensure maximum comfort - i.e. if the floor to seat height is 36”, the armrests should be about 26” in height. The majority of accent chairs comes pre-measured, meaning that you do not have to worry about matching the size of your chair to the size of its armrests!
The depth of your accent chair will mostly depend on how you would like to use it - an average armchair is about 35” deep, but if you plan on having a chair you can comfortably curl up in, consider depths of 45” and up.