(Power) Db to Watt

This is so simple, ...but I can't nail it!!

What is the conversion from Db to Watt?

[Robert Fogt]

0 decibel is equal to 1 picowatt per square meter. This corresponds to the faintest sound that can be detected by a person with good hearing.

A sound of 10 decibels means it is perceived as 10 times louder than 0 decibels.

Since decibels is a logarithmic unit of perceptive sound, I do not think there is a direct conversion between it and power.

I have seen conversions between decibel and power/area and between decibel and pressure, but I am fairly sure it would depend on the specific circumstances.

Perhaps someone in the audio field could shed more light on the subject.

This would be power conversion in RF terms. ie., 20Db @ 850Mhz. There is a power value in Watts. As in, so many Db equals so many watts.

I'm not clear on the conversion???

[Robert Fogt]

This is the closest thing I could find on the topic:

http://www.mogami.com/e/cad/db.html

Originally Posted by Scitnor

This is so simple, ...but I can't nail it!!

What is the conversion from Db to Watt?

108 DB = WATT?

dbm = 10^((WATTS - 30)/10)

30db = 1 watt (1000 mw)
27db = .5 watts (500mw)

for each 3 db gain or loss it doubles or halves.

33db = 2 watts (2000mw)

36db = 4 watts (4000mw)

24db = .25watts (250mw)

Forgot the formula!

Converting db to mw and mw to db

db=10*log(mw)
mw=anti-log(db/10)

Originally Posted by Scitnor

This is so simple, ...but I can't nail it!!

What is the conversion from Db to Watt?

DBM - 30 divide by 10 Inv log


60 dbm -30= 30 Divide by 10 = 3 log of 3 = 1000
50 dbm -30 = 20 Divide by 10 = 2 log of 2 = 100

+60 dbm =1000 watts
+50 dbm = 100 watts

each 3 db is twice or 1/2 of starting power

I am trying to convert dBm to Watts and none of the formula described so far work.

I have a reliable conversion from watts to dbm, but I cant reverse the situation, the formulas here don't reverse the result.

I am trying to do this in Excel, it is being used in a calculator for a Wifi Link budget.

This is the current Watts -> dBm (works) =10*LOG10(D8/ 0.001)

and in its current form, dBm -> Watts (doesn't work) =LOG((D9-30)/10)

'D8' (watts) and 'D9' (dBm) accept input from a user =)

If anyone can help, please email me [..guest link removed..]