Sound Level / Decibels Converter
Convert between decibels, bels, nepers and the power or amplitude ratios they represent.
1 bel = 1 bel
Most used level units
Popular level conversions
- Decibels to bels 1 dB = 0.1 B
- Bels to decibels 1 B = 10 dB
- Decibels to power ratios
- Power ratios to decibels
- Decibels to amplitude ratios
- Nepers to decibels 1 Np = 8.68589 dB
What is level?
Decibels express the ratio between two values on a logarithmic scale, which suits quantities such as sound, signal strength and gain that span many orders of magnitude. The bel is the base-10 logarithm of a power ratio; the decibel, one tenth of a bel, is the unit actually used.
A 10 dB increase means ten times the power; 3 dB is roughly double. For amplitudes such as sound pressure or voltage the ratio is squared, so 20 dB is ten times the amplitude. Sound levels (dB SPL) compare sound pressure with 20 µPa, the quietest sound a young person can hear.
Level units from smallest to largest
Every proportional level unit on the site, ordered by size and expressed in bels.
All 6 level units
Levels
Ratios
Frequently asked questions
How many decibels is double the power?
About 3.01 dB. Double the amplitude (sound pressure or voltage) is about 6.02 dB.
Is 60 dB twice as loud as 30 dB?
No. 60 dB carries 1,000 times the sound power of 30 dB, and is perceived roughly eight times as loud.