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Converts between power ratios and decibel scale for audio, RF, and other applications. Logarithmic scale matches human perception.
Fórmula
dBm = 10 × log10(P ÷ 0.001)
- P
- P value — Variable used in the calculation
Guia passo a passo
- 1dBm = 10 × log10(P ÷ 0.001)
- 2dBW = 10 × log10(P)
- 3Reverse: power (watts) = 10^(dBm ÷ 10) ÷ 1000
- 4Every 3 dB ≈ 2× power
- 5Every 10 dB ≈ 10× power
Exemplos resolvidos
Entrada
Power 1W
Resultado
30 dBm
Erros comuns a evitar
- ✕Confusing dBm (power) with dBV (voltage) with dBu (relative to 0.775V)
- ✕Adding dBm values instead of multiplying power
Perguntas frequentes
Why use decibels instead of watts?
Logarithmic scale compresses large ranges (1W to 1MW becomes 30 dBm to 60 dBm), easier comparison.
What's typical dBm for audio and RF?
Audio -20 to +4 dBu typical; WiFi transmit +17 to +30 dBm; cellular -30 to +33 dBm.
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