Enter the attenuation constant and length of the coaxial cable into the calculator to determine the attenuation in decibels; this calculator can also evaluate any of the variables given the others are known.

Coaxial Cable Attenuation Formula

The following formula is used to calculate the attenuation of a coaxial cable:

 Attenuation (dB) = 10 * log10(e^{(2 * α * L)})


  • Attenuation (dB) is the loss of signal strength in decibels
  • α is the attenuation constant of the coaxial cable
  • L is the length of the coaxial cable in meters

To calculate the attenuation of a coaxial cable, multiply the attenuation constant by twice the length of the cable. Take the exponential of the result, and then take the logarithm base 10 of that value. Multiply the result by 10 to obtain the attenuation in decibels.

What is a Coaxial Cable Attenuation?

Coaxial cable attenuation refers to the reduction in signal strength over the length of a coaxial cable. It is a critical factor in telecommunications and data transmission systems as it can significantly affect the quality and reliability of the signal being transmitted. The attenuation is caused by a combination of factors, including the resistance of the cable’s conductive elements, the dielectric loss in the cable’s insulation, and the leakage of the signal through the cable’s shielding. The level of attenuation is typically measured in decibels per unit length (dB/m), and it increases with frequency, meaning that higher-frequency signals will be more attenuated than lower-frequency signals. Therefore, it is crucial to consider the attenuation characteristics of a coaxial cable when designing and installing a data transmission system.

How to Calculate Coaxial Cable Attenuation?

The following steps outline how to calculate the Coaxial Cable Attenuation.

  1. First, determine the initial signal power (Pi) in decibels (dB).
  2. Next, determine the final signal power (Pf) in decibels (dB).
  3. Next, calculate the attenuation (A) using the formula A = Pi – Pf.
  4. Finally, calculate the attenuation in decibels per unit length (dB/m) by dividing the attenuation (A) by the length of the coaxial cable (L) in meters.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem:

Use the following variables as an example problem to test your knowledge.

Initial signal power (Pi) = 10 dB

Final signal power (Pf) = 5 dB

Length of coaxial cable (L) = 50 meters