Cable Attenuation Calculator (dB)
Estimate twisted-pair insertion loss (attenuation) for a structured-cabling run and check it against the ANSI/TIA-568.2-D 100 m channel limit.
- Pick the cable category Choose Cable category — Cat 5e (100 MHz), Cat 6 (250 MHz), or Cat 6A (500 MHz) — which sets the worst-case attenuation table used.
- Enter the run length Type the Run length in meters; insertion loss scales linearly as dB/100 m × length / 100.
- Select the test frequency Set Frequency to one of the tabulated TIA reference frequencies for that category (e.g. 1, 10, 100, 250, or 500 MHz).
- Calculate and check the channel Press Calculate to read the insertion loss in dB and whether the length stays within the 100 m channel maximum.
How far can I run Cat 6 cable?
ANSI/TIA-568.2-D limits a balanced twisted-pair channel to 100 m, made up of a 90 m permanent link plus up to 10 m of patch and equipment cords. The calculator flags any run length over 100 m as exceeding the channel limit regardless of category. Cat 6, Cat 6A, and Cat 5e all share this same 100 m channel maximum.
What is insertion loss on a network cable?
Insertion loss is the signal attenuation across the run, expressed in decibels. This tool multiplies the TIA-568.2-D worst-case component limit (dB per 100 m at the selected frequency) by length / 100. These are planning limits — a real installed run measures lower, so always field-certify with a cable analyzer.
Why are only certain frequencies available?
The calculator uses the standard TIA-568.2-D reference frequencies where horizontal-cable insertion-loss limits are tabulated, such as 1, 10, and 100 MHz for Cat 5e and up to 250 or 500 MHz for Cat 6 and Cat 6A. Each category only offers frequencies within its rated bandwidth, so you cannot enter an arbitrary value.