The network utilization is displaying more that 100%. Why is this so?

The network utilization is calculated based on the default interface bandwidth. If a interface bandwidth is not set as per the service provider internet bandwidth then there could be chance that utilization is shown wrongly. So set the proper interface bandwidth to get the correct network utilization value. Refer the following link for more details.
Network and please refer another article published in community - My device interface is showing interface utilization incorrectly or missing the utilization poll data points during specific period. What could be the reason?