Decimal to dB Conversion Calculator

This tool converts a decimal number to its deciBel (dB) equivalent.

Enter the decimal value and select either power or voltage. The tool will provide the dB value corresponding to this ratio.

🔁 dB to Decimal


In various fields like audio engineering, telecommunications, and signal processing, decibels (dB) are used extensively to express ratios of power or intensity in a logarithmic format.

This scale helps manage large variations in quantities more intuitively.

What is a Decibel?

A decibel (dB) is a logarithmic unit used to express the ratio of two values of a physical quantity, often power or intensity. The decibel scale reduces a wide range of ratios to a manageable scale by using logarithms, making it easier to work with very large or small numbers. This scale is relative and not absolute, which means it measures the ratio of two quantities rather than a direct measurement.

Formula for dB Conversion

To convert a decimal or linear ratio to decibels, different formulas are used based on the nature of the quantity being measured:

In the case of a power:

PdB = 10*Log10(P)

In the case of a voltage:

PdB = 20*Log10(V)

Example of Converting Decimal to dB

  • Power Ratio Example:
    Suppose you have two power levels, where one is 1000 times the other. The dB conversion would give a value of 30.
  • Voltage Ratio Example:
    If one voltage is 10 times another, then the dB conversion gives a value of 20.

Practical Applications

Decibels are widely used in several applications:

  • Audio Equipment: Adjusting the loudness of sound, where decibels measure the ratio of audio power levels.
  • Radio and Telecommunications: Signal strength is often measured in decibels to easily compare the power levels of transmitting and receiving signals.
  • Engineering and Science: Decibels help describe the efficiency of machinery and processes in terms of power input and output.