Convert dBm to mW
Enter power in decibel-milliwatts (dBm) and get the equivalent in milliwatts (mW), watts (W), and microwatts (µW).
Formula used: mW = 10(dBm/10)
Need to convert RF, wireless, or telecom power levels fast? This dBm to mW calculator gives you an instant, accurate conversion so you can work with practical linear power values.
What is dBm?
dBm is a logarithmic unit of power referenced to 1 milliwatt. It is widely used in Wi-Fi, cellular systems, radio frequency engineering, antenna measurements, and signal chain analysis.
- 0 dBm = 1 mW
- 10 dBm = 10 mW
- 20 dBm = 100 mW
- 30 dBm = 1000 mW (1 W)
How to convert dBm to mW
Use this equation:
Because dBm is logarithmic, every increase of 10 dB multiplies power by 10. A 3 dB increase is approximately a 2× power increase.
Step-by-step example
Convert 17 dBm to milliwatts:
- Divide by 10: 17 / 10 = 1.7
- Raise 10 to that power: 101.7 ≈ 50.1187
- Result: 17 dBm ≈ 50.12 mW
Quick reference table
| dBm | mW | W |
|---|---|---|
| -30 | 0.001 mW | 0.000001 W |
| -20 | 0.01 mW | 0.00001 W |
| -10 | 0.1 mW | 0.0001 W |
| 0 | 1 mW | 0.001 W |
| 3 | 1.995 mW | 0.001995 W |
| 10 | 10 mW | 0.01 W |
| 20 | 100 mW | 0.1 W |
| 30 | 1000 mW | 1 W |
| 36 | 3981.07 mW | 3.981 W |
| 40 | 10000 mW | 10 W |
Why this conversion matters
Engineers and technicians often read signal levels in dBm but need linear values for calculations and compliance checks. Converting to mW helps with:
- RF transmitter output planning
- Antenna system budgeting (EIRP checks)
- Wireless link budget analysis
- Lab measurements and equipment calibration
- Troubleshooting path loss and amplifier gain stages
Common mistakes to avoid
1) Assuming negative dBm means negative power
It does not. Negative dBm values are still positive power levels, just below 1 mW.
2) Mixing dB and dBm
dB is a ratio; dBm is an absolute power referenced to 1 mW.
3) Forgetting unit scale
mW, W, and µW differ by powers of ten. Always label units clearly in reports and calculations.
FAQ
Is 30 dBm equal to 1 watt?
Yes. 30 dBm = 1000 mW = 1 W.
How much is 20 dBm in mW?
20 dBm equals 100 mW.
Can I convert mW back to dBm?
Yes. Use: dBm = 10 × log10(mW).
Tip: Bookmark this page for quick RF power conversion while working on Wi-Fi design, LTE/5G testing, ham radio setups, or electronics projects.