What is the ideal size for a board?

After many years of serving on boards - or similar structures such as committees and councils - I’ve come to the conclusion that the ideal size of a board is between six and ten members. Whilst this isn’t an absolute rule, I have found it a very useful guide when deciding whether I will benefit from joining a board, and the board will benefit from me.

Fewer than six is not enough

Every board ideally needs the following skills:

On top of these, you also need skills and knowledge specific to the industry in which you operate. For example, a charity with high street shops might need board members with experience in:

Whilst you may have some members with multiple skills, it’s unlikely that you will cover everything with fewer than six.

More than ten is too many

Assuming you’re taking skills gaps into account when recruiting, each additional board member should add value. However, there is a point at which you get diminishing returns, where the marginal benefit of adding a board member is less than the cost. Large boards lead to the following problems:

I’ve been on boards which composed of representatives from lots of separate but related organisations, some of which ended up having fifteen, twenty or even more attendees. Most members didn’t get chance to speak in meetings, and we came away feeling frustrated and that nothing had been achieved.

Exceptions

There are of course exceptions to the ideal size. If you are a small company, you might have fewer than six directors - I’ve worked with small companies with between two and four directors. In the case of a small charity, the trustees and volunteers may be the same people.

If you are a multinational corporation, you might have smaller boards in each country and then a larger board at the multinational / headquarters level. Or you might delegate the majority of work to subcommittees, such as finance, HR and governance.