learn.howToCalculate
learn.whatIsHeading
Converts between power ratios and decibel scale for audio, RF, and other applications. Logarithmic scale matches human perception.
공식
dBm = 10 × log10(P ÷ 0.001)
- P
- P value — Variable used in the calculation
단계별 가이드
- 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
풀어진 예시
입력
Power 1W
결과
30 dBm
피해야 할 일반적인 실수
- ✕Confusing dBm (power) with dBV (voltage) with dBu (relative to 0.775V)
- ✕Adding dBm values instead of multiplying power
자주 묻는 질문
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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