Interface Error Rate Calculator

Work out interface error rate instantly with clear inputs, formula shown and shareable results.

About Interface Error Rate Calculator

A healthy Ethernet interface should show essentially zero errors, so any sustained error rate points at a physical problem. CRC errors specifically indicate corruption in transit — a damaged cable, dirty fibre connector, failing transceiver or duplex mismatch. Because TCP retransmits, even a very low error rate can produce noticeable throughput loss on long paths.

Formula

Error rate

error rate = error frames / frames received; errors per hour = errors / interval

Worked example

With the default values below, Interface Error Rate Calculator returns Frame error rate of 0.0002000%. Change any input above and every figure here is recalculated in your browser.

Inputs used

Frames receivedminimum 1: 4,200,000,000
Frames with errorsminimum 0: 8,400
CRC errors among themminimum 0: 6,200
Measurement intervalminimum 0.01 h: 24 h

Results

Frame error rate: 0.0002000%
Errors per hour: 350.0
Share of errors that are CRC failures: 73.8%
Assessment: Elevated errors - monitor and inspect the physical path

Step by step

1Values used
2Error rate
3Frame error rate= 0.0002000
4Errors per hour= 350.0
5Share of errors that are CRC failures= 73.8
6Assessment= Elevated errors - monitor and inspect the physical path

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 7 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

What error rate is acceptable?

Effectively zero. Ethernet is specified for a bit error rate of 10^-12 or better, so any counter incrementing steadily indicates a fault rather than normal behaviour.

What do CRC errors specifically indicate?

Corruption between the sender's checksum and your receipt: cabling, connectors, optics or electrical interference. Input errors without CRC failures more often mean buffer overruns.