Decibel Converter

Convert between decibels and linear ratios for various applications

Decibel Converter

Reference Level

Reference level for power-based calculations (e.g., signal power)

From:

Unit info

To:

Unit info

Conversion Formula:

ratio = 10^(dB/10)

From:

Decibels (dB)ℹ️

To:

Power/Intensity Ratioℹ️

Application References

Select a field to view commonly used reference values for various applications.

Common Conversions

Decibel Facts

• The decibel is a logarithmic unit named after Alexander Graham Bell, the inventor of the telephone.
• Every +3 dB increase represents a doubling of power, while every +6 dB increase represents a doubling of voltage or current.
• A +10 dB increase represents a 10× increase in power, while a +20 dB increase represents a 10× increase in voltage.
• In telecommunications, signal strength of -70 dBm is considered excellent, while -100 dBm is very poor.
• In RF engineering, 0 dBm equals 1 milliwatt of power, while 30 dBm equals 1 watt.

Decibel Applications

Telecommunications:

Signal strength (dBm, dBW)
Signal-to-noise ratio (dB)
Antenna gain (dBi, dBd)
Cable loss (dB/m)

Audio Engineering:

Signal levels (dBu, dBV)
Digital audio (dBFS)
Gain staging (dB)
Dynamic range (dB)

Electronics:

Amplifier gain (dB)
Filter attenuation (dB)
EMC testing (dBµV/m)
Return loss (dB)

Optics:

Fiber optic loss (dB/km)
Optical return loss (dB)
Laser power (dBm)
Receiver sensitivity (dBm)

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Decibel Visualized

Logarithmic Scale Visualization

10.00 dB

Above Reference

Linear Ratio: 10.00 (Power Ratio)

Technical Applications

Reference Level (0 dB)

Equal to reference power

Double Power (+3 dB)

Power doubled from reference

10× Power (+10 dB)

10 times the reference power

1000× Power (+30 dB)

1000 times the reference power

1/10 Power (-10 dB)

One-tenth the reference power

Technical Formulas:

Power: dB = 10 × log₁₀(P₂/P₁)

Voltage: dB = 20 × log₁₀(V₂/V₁)

Power from dB: P₂/P₁ = 10^(dB/10)

Voltage from dB: V₂/V₁ = 10^(dB/20)

Key reference points:

+3 dB = 2× power

+6 dB = 2× voltage

+10 dB = 10× power

+20 dB = 10× voltage

Mobile tip: Swipe left or right on the unit dropdown to quickly change units, or use the arrow buttons

About the Decibel Converter

Convert between decibels and linear ratios for various applications All conversions run instantly in your browser and nothing you enter is sent to a server.

Common Conversion Formulas

From	To	Formula
Decibels (dB)	Power Ratio (P/P₀)	dB = 10 × log₁₀(P/P₀)
Decibels (dB)	Voltage/Current Ratio (V/V₀)	dB = 20 × log₁₀(V/V₀)
dB SPL	Sound Pressure (p)	dB SPL = 20 × log₁₀(p/p₀) where p₀ = 20 μPa

Decibel Converter