• 📡 Coax Loss Calculator

    Estimate signal loss through coaxial cable based on cable type, frequency, cable length, and connector loss. See the estimated total attenuation, power remaining, and output power.
    Built-in cable values are approximate reference values. Actual attenuation varies by manufacturer and cable construction.
    Enter the operating frequency in MHz.
    Custom Cable Attenuation
    Enter an attenuation value from your cable manufacturer's specification sheet and the frequency at which that value applies.
    Cable Run
    Additional Loss
    Optional estimate for connector losses.
    Use the manufacturer's value when available.
    Power

    Estimated Cable Loss

    Total Estimated Loss —
    Cable Loss —
    Connector Loss —
    Power Remaining —
    Output Power —
    Estimated Power Remaining 100%
    Note: This calculator provides an estimate. Real coax attenuation can vary with manufacturer, cable age, temperature, installation quality, connectors, adapters, bends, impedance mismatch, VSWR, and other factors. For critical RF systems, use the attenuation data supplied by the cable manufacturer.
    How does the Coax Loss Calculator work?

    A coaxial cable does not deliver all of the signal entering one end to the other end. Some energy is lost as the signal travels through the cable. This reduction is called attenuation and is commonly expressed in decibels.

    Cable loss generally increases as frequency increases and as the cable run becomes longer. This means a long cable carrying a high-frequency signal can experience much more loss than a short cable carrying a lower-frequency signal.

    The calculator estimates attenuation for the selected cable and frequency, scales that loss to the length of the cable, adds optional connector losses, and then calculates how much input power remains after the total attenuation.
    Tip: If you're planning a long RF cable run, compare several coax types before installation. A thicker, lower-loss cable may preserve significantly more signal at higher frequencies. For the most accurate result, select Custom Cable and enter the attenuation specification from the exact cable manufacturer's datasheet.

  • A Coax Loss Calculator helps estimate how much signal or power may be lost as it travels through a coaxial cable. This can be useful when planning RF systems, antennas, radio equipment, wireless installations, test setups, communication systems, and other electronics that use coaxial cable.

    Choose a common coax type such as RG-58, RG-59, RG-6, RG-8X, RG-213, LMR-195, LMR-240, LMR-400, or LMR-600, then enter your operating frequency and cable length. The calculator estimates the attenuation of the cable run in decibels.

    Coaxial cable loss depends heavily on both length and frequency. Longer cables generally produce more attenuation because the signal has farther to travel. Loss also generally increases as frequency rises, which means a cable that performs well at a relatively low frequency may lose considerably more signal when used at a much higher frequency.

    The calculator also lets you include connector loss. Connectors, adapters, and other components in a signal path can introduce additional insertion loss, so including them can provide a more complete estimate of the total signal loss.

    If you enter an input power, the calculator converts the total dB attenuation into a power ratio and estimates how much power reaches the other end of the cable.

    For example, a loss of approximately 3 dB corresponds to roughly half of the original power remaining, while a 10 dB loss corresponds to about one-tenth of the original power.

    The Custom Cable option lets you enter attenuation information from a specific cable's datasheet. This is especially useful because two cables with the same general designation can have different performance depending on the manufacturer, materials, shielding, conductor construction, and exact model.

    Built-in cable values should be treated as approximate reference values rather than exact manufacturer specifications. Actual attenuation can also be affected by temperature, cable condition, installation quality, connectors, adapters, bends, impedance mismatch, VSWR, and other factors.

    For critical RF installations, always check the attenuation chart or datasheet supplied by the manufacturer of the exact cable you plan to use.

    Tip: Pay close attention to frequency when comparing coax cables. A cable that loses only a small amount of signal at a lower frequency may experience substantially more attenuation at higher frequencies. For long runs or high-frequency applications, using a lower-loss cable—or shortening the cable run—can preserve significantly more of the original signal.