Decibel gain converter
Convert decibels into the ratio they stand for. Ten dB is ten times the power, but only 3.16 times the voltage.
That's about the same as a hundred times. That is 100× the power, or 10× the voltage.
What it means
How much is that?
These are plain ratio decibels. Decibels with a letter after them — dBm, dBW, dBµV — are levels against a fixed reference, which is a different page.
Every unit
Your gain in every unit
Learn
Three things worth knowing
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3 dB is double, 10 dB is ten times
In power. Those two numbers cover most mental arithmetic: 6 dB is four times, 20 dB is a hundred, 60 dB is a million.
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From the bel, and Bell
Telephone engineers measured cable loss in "miles of standard cable", then replaced it with the bel, named for Alexander Graham Bell. A whole bel proved too coarse, so the tenth became standard.
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10 log or 20 log
Use 10·log for power and 20·log for voltage. Applying the wrong one doubles or halves your answer in dB, which is a factor of a hundred in the thing you measured.
Shortcuts
Popular gain conversions
Background
About the decibel
A decibel is a ratio on a logarithmic scale, so gains add instead of multiplying: three stages of 10 dB give 30 dB, which is a thousand times the power.
The catch is the factor of two: for power it is 10·log₁₀, for amplitude — voltage, current, sound pressure — it is 20·log₁₀. The same physical change gives the same dB either way.