Coaxial Cable Loss Calculator

The loss table stores measured attenuation at six reference frequencies (100 MHz through 5800 MHz) because skin-effect and dielectric losses inside the cable both worsen as frequency rises, pushing current toward the conductor's surface and increasing effective resistance. The calculator linearly interpolates between whichever two reference points bracket your entered frequency, so a value like 1200 MHz is blended proportionally between the 900 MHz and 1800 MHz figures rather than looked up directly.

The interpolation table tops out at 5800 MHz, so for anything higher the calculator extrapolates by continuing the slope between the 2400 MHz and 5800 MHz points. That's a reasonable approximation close to 5800 MHz, but it's not a measured value, so loss estimates well beyond the table's range (well into the tens of GHz) should be treated as rougher guesses.

Each connector adds a flat per-connector loss (0.3 dB by default, editable to match your connector type) multiplied by how many you enter, then added directly to cable loss for the total system figure. On a short run of low-loss cable like LMR-600, two or three connectors can represent a larger share of total loss than the cable itself, which is why minimizing connector count matters as much as cable choice on short jumpers.

Loss per 100 feet comes straight from the interpolated table, but loss per meter is derived afterward by taking your computed total cable loss and dividing it by your cable length converted from feet to meters (length × 0.3048). It's provided so you can compare against cable data sheets that publish specs in dB per meter rather than dB per 100 feet, which is common for cable sourced outside the US.