What dB change represents a factor of two increase or decrease in power?

The decibel (dB) is a logarithmic unit used to express the ratio of two values of a physical quantity, most commonly power in radio applications. The formula for power changes in decibels is 10 * log10(P2/P1). When the power is doubled (a ratio of 2), the calculation becomes 10 * log10(2). Since the base-10 logarithm of 2 is approximately 0.301, multiplying by 10 gives approximately 3.01 dB. Therefore, a 3 dB increase means the power has doubled, and a 3 dB decrease means it has halved. Distractors like 6 dB are common mistakes made by confusing the power rule with the voltage rule. For voltage or current, a factor of two results in a 6 dB change because the formula uses a multiplier of 20 instead of 10.