Watts <> dBm <> Volts Converter

Site Home

Electronics Home

Calculator Index

About Us

Privacy Policy

This calculator converts between watts, dBm, volts and dBmV.

Select the Impedance then enter any one of the other parameters below and the rest will be calculated automatically

Impedance (Ω): Common in RF and Microwave Systems
Common in TV and Video Systems
Common in Audio Systems
Custom Value
 
milli Watts (mW):
Watts (W):
 
dBm:
dBW:
 
VRMS:
VPeak: Assuming a sine wave
VP-P: Assuming a sine wave
 
dBmV: dB relative to 1mV RMS. Often used in the cable TV industry and only valid in 75Ω systems



Most RF engineers will have memorised the following values:

dBmmWNotes
0 1Exact by definition of dBm
3 23 dBm is actually 1.995 mW but that's near enough for most practical purposes
10 10Exact
+3 ×2Adding 3 to the power in dBm is the same as multiplying the power in Watts by two (actually 1.995 but that's near enough for most practical purposes)
+10×10Adding 10 the the power in dBm is exactly the same as multiplying the power in Watts by 10



Whilst I try to keep the information on this site accurate, I'm only human and I do occasionally make mistakes. I therefore advise you to check any information before using it for anything important. If you do find any errors, please let me know so that I can correct them.

Click here to report an error on this page.

This page was last changed on: 02 August 2021.

Thanks for visiting my site.