dB to Percent Converter

Convert decibels (dB) to percentage (%) — and back. Results shown for both amplitude and power ratios instantly.

dB → Percent (%)
dB
Common Values
Amplitude
%
10(dB/20) × 100
Power
%
10(dB/10) × 100
OR
Percent (%) → dB
%
Common Values
Amplitude dB
dB
20 × log10(% / 100)
Power dB
dB
10 × log10(% / 100)

dB to Percent Conversion Table — Amplitude & Power

dB Amplitude % (Voltage/Pressure) Power % (Energy/Intensity) Common Use
+6 dB199.526%398.1072%Double voltage / 4× power
+3 dB141.254%199.5262%Half power increase (+1.41× amp)
0 dB100.000%100.0000%Reference level (no change)
-1 dB89.125%79.4328%Slight reduction
-3 dB70.795%50.1187%Half power (−29.3% amp)
-6 dB50.119%25.1189%Half amplitude / ¼ power
-10 dB31.623%10.0000%1/10 power (31.6% amp)
-20 dB10.000%1.0000%10% amplitude / 1% power
-40 dB1.000%0.0100%1% amplitude / 0.01% power
-60 dB0.100%0.0001%0.1% amp / 0.0001% power
Amplitude vs Power: Use the amplitude formula (÷20) for voltage, sound pressure, or electric field strength. Use the power formula (÷10) for energy, intensity, or power measurements. At 0 dB, both equal 100%. At −3 dB, amplitude ≈ 70.79% but power ≈ 50%.
dB to Percent Calculator – Decibel to Percentage