Convert between linear values and decibels for power and voltage.
Conversion Parameters
Calculation Results
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About this calculator
Quick Reference
dBmReference P₀ = 1 mW
dBWReference P₀ = 1 W
dBVReference V₀ = 1 V
dBuReference V₀ = 0.775 V
dB SPLReference P₀ = 20 μPa
Overview
The decibel (dB) is a logarithmic unit used to express the ratio of two values of a physical quantity, often power or intensity. It is also used to express absolute levels relative to a reference value.
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Pro Tips
For Power: A change of 3 dB is roughly a doubling of power.
For Voltage/Amplitude: A change of 6 dB is roughly a doubling of voltage.
A negative dB value means the quantity is less than the reference.
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Fun Facts
"The decibel is named after Alexander Graham Bell, the inventor of the telephone."
"The human ear perceives loudness logarithmically, which is why decibels are used for sound measurement."
