In deciding the optimal numbers for an organisation's board, the decision makers should reflect on these matters. Our advice and recommendation is generally 8 -10 members as being the optimal number, with 8 more appropriate for a larger more commercial operation and 10 more suitable for a smaller organisation or sporting club. A simple filter is the staffing arrangements. For those organisations that employ a CEO/ Manager, then 8 is the preferred number, whereas if resources are less and staffing reflects this, then 10 would be more suitable to better support the business without the downsides of a much bigger board (or Committee as a better description). Furthermore, if the opportunity presents itself, it is advised to start with less and appoint additional members if deemed necessary; it' much easier to recruit than downsize!
In summary, there is no "off the shelf" system for the ideal number of board members. Whilst the principles of good governance are consistent across organisation types and sizes, structures are proprietary and should reflect the strategy and culture of the organisation; however like all matters in relation to governance, the business leaders must think about and plan to create their preferred structure to achieve the best result for their organisation.