# OSPF ## OSPF Cost ``` cost = reference bandwidth / configured bandwidth of interface in kbps reference bandwidth = 100,000 kbps ```
Interface speedOSPF Cost
100 Mbps1
10 Mbps10
6 Mbps17
5 Mbps20
4 Mbps25
3 Mbps33
2 Mbps50
1.5 Mbps67
1 Mbps100
768 Kbps130
512 Kbps195
384 Kbps260
256 Kbps391
128 Kbps781
64 Kbps1563