# Math, when 2 equals .2

4

In my last post I talked about a 2mW user.  Specifically I said:

5. Or, with roughly 250 million Firefox users, 50kW is 2 milliwatts/user (or 144Wh/month).

I haven’t stopped thinking about that number as a metric of measuring efficiency or how much power it takes to do work (provide services) for some number of Firefox users.  I thought it’d be more interesting to trend wattage/user over time than just raw wattage (which is still too abstract for me to wrestle with).

My only problem is that my graphing tool kept spitting about numbers like:

`241.24 μW`

I had to stare at it bit before it clicked.

`50kW/250m users = .0002 watts/user`

`50,000 W/250,000,000 users = .0002 watts/user`

That comes out to .2mW/user (or 200μW/user). Quite frankly I’m embarrassed I didn’t catch my mistake earlier. I should have used something like this or this before posting!

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The milliwatt (symbol:mW) is equal to one thousandth (10-3) of a watt. The microwatt (symbol:μW) is equal to one millionth (10-6) of a watt.

Categories: Mozilla

# 4 responses

1. ### What is this field?wrote on March 4th, 2009 at 3:08 am:

The post you link to has been corrected to 2 micro Watt rather than 200 micro Watt.

2. ### mrz wrote on March 4th, 2009 at 8:31 am:

Yep, fixed that this morning too.

3. ### Jesse Ruderman wrote on March 4th, 2009 at 2:27 pm:

I’d say you had a Verizon Moment there.

4. ### Funtomaswrote on March 5th, 2009 at 2:27 am:

I like the post’s title. Nice way making errata. I wonder if it could help to save Enron.