Enter the initial power level and the final power level into the calculator to determine the Db gain.

DB Gain Formula

The following formula is used to calculate a dB gain.

dB = 10log10 (P2/P1)

  • Where dB is the decibel gain (decibels)
  • P2 is the final power level (watts)
  • P1 is the initial power level (watts)

DB Gain Definition

What is a dB gain? A dB gain, also known as a decibel gain, is a measure of power increase that’s expressed as a log value of the ratio of the final power to the initial value.

Example Problem

How to calculate dB gain?

  1. First determine the initial power level.

    For this example, the initial power level is 1,000 watts (1kW)

  2. Next, determine the final power level.

    After the system power had been increased to full power, the final power level is found to be 3,000 watts.

  3. Finally, calculate the decibel gain.

    Using the formula above, calculate the decibel gain. dB = 10 * log (3000/1000) = 10*log(3) = 4.771 decibels.

About dB Gain

Is a higher dB gain better? In general, the dB gain is used to describe the amplification of the power of a certain signal. In almost all cases, a higher dB gain is better, which means the signal booster is performing well.

Can dB gain be negative? If a signal booster or system decreases the power enough, the dB gain will end up being negative. For example, if the original power is 1000 watts, and the system is reduced to 1 watt, the dB gain would be 10*log(1/1000) = -30 decibels.