Nowhere does the Bible identify a specific number of elders that should lead each local congregation. Therefore, churches are left to godly wisdom and prudence to help determine how many men God has called to lead them.
Some churches institute a system for how many elders they will have, whether by setting an exact number of elders or by determining a ratio of elders to members. However, both of these systems have serious disadvantages. In both, the church runs the risk of putting itself in a situation where it will either need to fill a quota with men who are not qualified, or it can’t recognize godly, qualified men who should serve as elders because their quota is full.
On balance, it seems best for each church not to decide ahead of time how many elders they think they should have, but to seek to humbly recognize those men whom God has gifted to serve as elders and pray that the Lord would raise up a sufficient number to shepherd his church.
(Some of this material has been adapted from Benjamin Merkle, 40 Questions About Elders and
Deacons [Grand Rapids: Kregel, 2008], pp. 166-168)