Case 1
- Power level (dBW)
- 30dBW
1,000.000000W
Open with these valuesdBW to Watts Calculator
1,000.000000W
Result: 1,000.000000 WdBW counts decibels above one watt, so 0 dBW is 1 W and 30 dBW is 1 kW. It is the same scale as dBm, shifted by exactly 30 dB: dBm = dBW + 30. Radar, satellite and broadcast work in dBW because the powers are watt-scale; receivers are quoted in dBm because they are not.
Worked examples
Case 2
- Power level (dBW)
- 0dBW
1.000000W
Open with these valuesCase 3
- Power level (dBW)
- -30dBW
0.001000W
Open with these valuesHow it's calculated
P(W) = 10^(dBW ÷ 10)
- StepEnter the level in dBW; negative values mean less than a watt.
- ResultRead the power in watts. Add 30 to the level to get dBm.
Reference table
| Level (dBW) | What it is | Power (W) |
|---|---|---|
| −30 | 1 mW, the same as 0 dBm | 0.001000 |
| 0 | 1 W — the reference point | 1.000000 |
| 3 | Roughly double, the 3 dB rule | 1.995262 |
| 10 | 10 W | 10.000000 |
| 20 | 100 W FM transmitter | 100.000000 |
| 30 | 1 kW radar pulse | 1000.000000 |
Questions
What does dBW mean?
Decibels relative to one watt. 0 dBW is 1 W, 10 dBW is 10 W and 30 dBW is 1000 W. Negative values are valid and simply mean less than a watt; dBW is standard in radar, satellite and broadcast engineering.
How do I convert dBW to watts?
P(W) = 10^(dBW ÷ 10). Raise ten to the power of the level divided by ten, and that is the answer in watts directly — no division by a thousand, unlike dBm. For 30 dBW: 10^3 = 1000 W.
What is the difference between dBW and dBm?
Only the reference. dBW counts from one watt, dBm from one milliwatt, and a ratio of a thousand is 30 dB, so dBm = dBW + 30 always. 0 dBW is 30 dBm; 30 dBW is 60 dBm.
Why does +10 dBW mean ten times the power?
Because dBW is defined as 10 × log₁₀(P ÷ 1 W), so P = 10^(dBW ÷ 10) W. Every 10 dB adds one to the exponent and multiplies the power by ten. Every 3 dB roughly doubles it, which is why the table above shows 3 dBW as almost exactly 2 W.
What are typical dBW values for real equipment?
A 100 W FM transmitter is 20 dBW, a 1 kW radar pulse is 30 dBW, and a large satellite uplink at 50 kW is about 47 dBW. A receiver input of −30 dBW is one milliwatt, before any amplification. Those anchors make a link budget easy to sanity-check.
Sources and last check
Information, not professional advice.