EIGRP uses a composite metric of bandwidth and delay by default similar to IGRP but modifed by a factor of 256. This combination is known as the feasible distance. http://www.cisco.com/en/US/tech/tk365/technologies_white_paper09186a0080094cb7.shtml#eigrpmetrics
Although bandwidth and delay are the recommended values commonly used for manipulation, there are a total of 5:
Bandwidth: in kilobytes, a value that can be adjusted per interface using the bandwidth command. Use with caution as this can affect other protocols as well.
Delay: in microseconds, adjusted using the delay command. Delay is the preferred value adjustment.
Reliability: as an integer value between 1 and 255. 1 is unreliable; 255 most reliable.
Load: as an integer value between 1 and 255. 1 is least loaded.
MTU: as a byte value; the least value recorded in the path. MTU is maximum transmission unit and is not used in the calculation.
Default integer values:
K1 = 1 K2 = 0 K3 = 1 K4 = 0 K5 = 0
Metric calculation (actual):
metric = [K1 * bandwidth + (K2 * bandwidth) / (256 – load) + K3 * delay] * [K5 / (reliability + K4)]
Equation after default K5 (0) value:
[K1 * bandwidth + (K2 * bandwidth)/(256 – load) + K3 * delay]
And further given K2 = 0 (per the default):
metric = bandwidth + delay
Important; the reasons an EIGRP adjacency will not form other than a physical link problem:
Mismatched AS, not in the same subnet and mismatched K values.