Watts To dB Converter - Calculator HD

Power → dB Calculator

Input power and unit to get dBm, dBw, and dBk.

Power:

dB Results

dBm (ref 1 mW)

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dBw (ref 1 W)

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dBk (ref 1 kW)

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Formulas (using power in watts P_W):

dBm (ref 1 mW): dBm = 10·log₁₀(P_W · 1000)
dBw (ref 1 W): dBw = 10·log₁₀(P_W)
dBk (ref 1 kW): dBk = 10·log₁₀(P_W / 1000)

Converting Watts to decibels (dB) is a frequent necessity in electronics, RF engineering, acoustics, and communication systems. Decibels enable power levels to be represented on a logarithmic scale, facilitating the comparison of very large or small values.

What Is a Watt?

A watt (W) represents the rate at which energy is consumed or transferred.

1 Watt = 1 Joule per second

1 Milliwatt (mW) = 0.001 W

1 Kilowatt (kW) = 1000W

What is dBm?

dBm stands for decibel-milliwatts.

It expresses power relative to 1 milliwatt (mW).

0 dBm = 1 mW

What is dBw?

dBW stands for decibel-watts, referenced to 1 watt (W).

0 dBW = 1 W

What is dBk?

dBk refers to decibel-kilowatts, relative to 1 kilowatt (kW).

0 dBk = 1 kW

Watts to dB Conversion Formulae

General Formula (Power Ratio to dB)

dB = 10 \log_{10} (\frac{P}{P_{ref}})

Where:

$P$ = power in Watts
$P_{ref}$ = reference power (1 mW, 1 W, or 1 kW)

Watts to dBm Formula

dBm = 10 \log_{10} (\frac{P (W)}{0.001})

Because 1 mW = 0.001 W

Watts to dBw Formula

dBw = 10 \log_{10} (P (W))

Watts to dBk Formula

dBk = 10 \log_{10} (\frac{P (W)}{1000})

Because 1 kW = 1000 W

How to convert Watts to dB using our calculator?

Enter the “Power”
Select the applicable unit, i.e., W, mW, or kW.
Click “Calculate” to find dBm, dBw, and dBk.