EIGRP Metric Calculator
Compute the EIGRP composite metric using bandwidth, delay, and K-values.
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EIGRP Composite Metric Formula
The Formula
The EIGRP composite metric is calculated as:
Metric = [K1 × BW + (K2 × BW) ÷ (256 − Load) + K3 × Delay] × [K5 ÷ (Reliability + K4)] × 256
Where BW = 107 ÷ min_bandwidth_in_kbps (scaled by 256 in the formula below) and Delay = sum_of_delays_in_tens_of_µs. With default K-values (K1=1, K3=1, others=0), this simplifies to Metric = (BW + Delay) × 256.
Why Bandwidth and Delay?
Bandwidth represents the slowest link along the entire path — a single 1.5 Mbps T1 link bottlenecking a path of Gigabit links dominates the metric. Delay represents cumulative latency across all outgoing interfaces, making hop count indirectly relevant.
When to Change K-Values
The default K-values (1, 0, 1, 0, 0) are almost always correct. Changing K-values requires identical configuration across all routers in the EIGRP domain — mismatched K-values prevent neighbor adjacencies from forming. Only consider tuning K2 (load), K4, or K5 (reliability) if you have a specific policy-based routing requirement.
EIGRP Wide Metrics
Modern EIGRP implementations (EIGRP Wide Metrics) use a 64-bit metric space with different scaling factors, supporting higher-bandwidth links (100 Gbps+) without losing path discrimination. The classic 32-bit metric formula above is still the standard for CCNA certification and legacy networks.
Frequently Asked Questions
What does the EIGRP metric number mean?
The metric is a relative value used to compare paths within the same EIGRP topology table. A lower metric means a better path. The metric itself has no absolute meaning — it only matters relative to other paths to the same destination. The route with the lowest feasible distance becomes the successor (best path).
Can I manually set the EIGRP metric?
Yes. Use the offset-list command under EIGRP router configuration to add an offset to the metric for specific routes. This is useful for influencing path selection without changing interface bandwidth or delay.
What happens if K-values mismatch between routers?
EIGRP routers with mismatched K-values will not form an adjacency. The routers exchange K-values in Hello packets, and if they differ, the neighbor relationship is rejected. Always verify K-value consistency across the EIGRP domain, especially when connecting to third-party or multi-vendor networks.