OneTool

Decibel Converter

dB ↔ ratios and dBm reference conversions.

Quantity
Direction

Result

3.01 dB

What is this tool?

Decibels express ratios on a log scale: power ratios use 10·log10, voltage (same impedance) use 20·log10. dBm is power relative to 1 mW. This converter switches between those representations for quick checks.

How to use it

  1. Choose the conversion type (power ratio, voltage ratio, or dBm).
  2. Enter the known value.
  3. Read the converted result.