logarithmic ratio quantity · International · Modern
1 bel = 10 decibels. For a power-like ratio, 1 B corresponds to a ratio of 10:1.
Converter
logarithmic ratio quantity · International / acoustics / signals · Modern
decibel
exact
- Record
- M562
- Definition quality
- Standardized
- Conversion mode
- formula
- Calculator
- Formula-based
Definition
The decibel is one tenth of a bel and expresses a base-10 logarithmic ratio. It is not inherently a unit of sound pressure.
Reference value
decibel converts through a formula rather than a simple multiplier.
History & use
BIPM and NIST accept the bel and decibel for use with SI but stress that the quantity and reference value must be stated.
Modern use
Modern use is context-dependent and varies by region or measurement system.
Sources & evidence
Source tier — · confidence high
Related measurements
logarithmic ratio quantity · SI-compatible / electrotechnology / acoustics · Modern
The neper expresses logarithmic ratios using natural logarithms rather than base-10 logarithms.