EIGRP Metric Calculator
Calculate the composite EIGRP metric from minimum bandwidth and cumulative delay along a path, using default K-values.
Inputs
The slowest link's bandwidth in the path, in Kbps (e.g. 1 Gbps = 1,000,000 Kbps).
Sum of delay along the path, in tens of microseconds (Cisco convention).
EIGRP Composite Metric
3,072,000
Bandwidth Term (10^7 / min_bw)
10,000.00
Delay Term (sum of delay / 10)
2,000.00
Note
Default K-values (K1=1, K3=1, K2=K4=K5=0) applied — the standard EIGRP composite metric formula.
Step by step
Values used
Minimum Bandwidth Along Path = 1,000 Kbps; Cumulative Delay = 2,000 µs (tens); K-Value Profile = Default (K1=1, K3=1, others 0)
EIGRP composite metric (default K-values)
metric = 256 × ((10^7 / min_bandwidth_Kbps) × K1 + (total_delay / 10) × K3)
EIGRP Composite Metric
= 3,072,000
Bandwidth Term (10^7 / min_bw)
= 10,000.00
Delay Term (sum of delay / 10)
= 2,000.00
Note
= Default K-values (K1=1, K3=1, K2=K4=K5=0) applied — the standard EIGRP composite metric formula.
How it works
EIGRP computes a composite metric from the slowest (minimum) bandwidth along the entire path and the cumulative delay of every link in the path, combined using tunable K-value weights. With Cisco's default K-values (K1=1, K3=1, and K2=K4=K5=0), the formula reduces to 256 times the sum of a bandwidth term (10,000,000 divided by the minimum bandwidth in Kbps) and a delay term (the total delay in tens of microseconds). Because it uses the single slowest link rather than summing bandwidth, and adds cumulative delay, EIGRP's metric reflects real path characteristics more richly than RIP's simple hop count, while remaining computationally lighter than full link-state flooding.
Formula
EIGRP composite metric (default K-values)
metric = 256 × ((10^7 / min_bandwidth_Kbps) × K1 + (total_delay / 10) × K3)
- B_min
- Minimum bandwidth along the path (Kbps)
- D_sum
- Cumulative delay (tens of microseconds)
- K_1
- Bandwidth weight (default 1)
- K_3
- Delay weight (default 1)
Frequently Asked Questions
Why does EIGRP use the minimum bandwidth instead of summing all link bandwidths?
A multi-hop path can never move data faster than its slowest link — that link is the bottleneck for the entire path — so EIGRP correctly uses only the minimum bandwidth encountered along the route rather than summing or averaging bandwidths, which would misrepresent the path's true throughput ceiling.
What do the EIGRP K-values control?
K1 through K5 weight the contribution of bandwidth, load, delay, reliability, and MTU respectively to the composite metric formula. Cisco's default enables only K1 (bandwidth) and K3 (delay), effectively ignoring load, reliability, and MTU unless an administrator explicitly changes the K-value profile — all routers in an EIGRP domain must use matching K-values or they cannot form neighbor relationships.
Why is the metric multiplied by 256?
The scaling factor of 256 originates from EIGRP's predecessor, IGRP, which used an 8-bit (0-255) metric internally; EIGRP retained backward compatibility with IGRP by scaling its wider composite metric by 256, preserving the ability to redistribute routes between the two protocols with a consistent conversion factor.