learn.howToCalculate
learn.whatIsHeading
Converts between power ratios and decibel scale for audio, RF, and other applications. Logarithmic scale matches human perception.
الصيغة
dBm = 10 × log10(P ÷ 0.001)
- P
- P value — Variable used in the calculation
دليل خطوة بخطوة
- 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
أمثلة محلولة
الإدخال
Power 1W
النتيجة
30 dBm
أخطاء شائعة يجب تجنبها
- ✕Confusing dBm (power) with dBV (voltage) with dBu (relative to 0.775V)
- ✕Adding dBm values instead of multiplying power
أسئلة شائعة
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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