How Much Does a Single Search Cost Google?

I was wondering how much it costs Google to perform a single search. So I searched in Google, and was not able to find any readily available data that looked reliable. So I used up the better part of Saturday morning working on creating my own number.
I was able to find some ComScore data on total searches from July 2009, and I got Google's financials from 2009 from the SEC site.
My calculation? I estimate that it costs Google .68 cents per search in July 2009 in direct costs, and another .50 cents in overall operating costs, or a total of 1.18 cents per search. That's considerably more than I would have expected. (Please check my math and sources!)
I also found that for 78 billion searches in the month of July 2009, Google needed 3.442 B of capital equipment to support those searches. (Excludes YouTube and other non-search capital). Thus each search performed that month needed 4.4 cents of capital equipment. I did notice on Google's later financials that their capital costs didn't go up that much, so their capital cost per search is likely dropping. (plummeting?)
I'm wondering if anyone has newer data or more accurate data that they could plug in? Please let me know in the comments section.
Here is a summary of my estimate:


July 2009






Worldwide Google Searches K


Age 15+ Home & Work Worldwide

Cost of Revenues $K


Represents 70% that is search related

Direct Cost/Search




Search Related Operating Costs $K


Note: Click on Income Statement

Op Cost/Search




Total Cost Per Search



July 2009 - My estimate


Capital Required $K



Represents 70% that is search related

Cap/Per Search $



   Google Q3 09 Monthly Revenue $K


 2009 Q3 earnings release  Not quite true, but I'm assuming all revenue from search

Revenue Per Search



Cap/Per MM Searches/Mo



$44K of capital gets you 1 million searches/mo capacity


(that’s 33K searches a day; 1.4K searches/hr


23 searches/minute - hmmm. Seems like a lot of 


capital to support just 23 searches per minute! Remember, though; this includes the cost to index the ENTIRE WORLD of web pages to support those searches.


# Seconds in a Month



Searches Per Second



In July 2009

K Searches/Sec



Cap Cost per K Search/sec



It takes $116 million in capital to support 1,000 searches per second and the indexes to all the web pages in the world (roughly)


Attached below is a PDF of my background calculations. This PDF was made from an Apple Numbers Spreadsheet.


Here is the Apple Numbers Spreadsheet with all my source information. Please let me know if you find errors. Apple Numbers is nice because it lets you combine many spreadsheets on one "canvas."


Here is the Excel spreadsheet that Numbers generates for compatibility. I regret I didn't name the tables before exporting, but you'll get the idea as you click to the various tables. (Note: There may be problems with the Posterous viewer for this file type, so if you can't see this file, it isn't you! Also, for some reason, Posterous only lets you view the Excel file, while it lets you download the Numbers file.)
Update: 6PM 1-15-2010
Found this data from Nielson Us Rankings for February 2010

Top 10 Search Providers for February 2010, Ranked by Searches (U.S.) Rank Provider Searches (000) Share of Searches   All Search 9,174,408 100.0% 1 Google Search 5,980,116 65.2% 2 Yahoo! Search 1,294,261 14.1% 3 MSN/Windows Live/Bing Search 1,142,344 12.5% 4 AOL Search 206,969 2.3% 5 Search 175,074 1.9% 6 My Web Search Search 91,288 1.0% 7 Comcast Search 55,122 0.6% 8 Yellow Pages Search 27,002 0.3% 9 NexTag Search 26,461 0.3% 10 Network Search 24,681 0.3% Source: The Nielsen Company

They show Google having done 9.2 billion searches in the US in February 2010, vs 78 billion searches worldwide for Google reported by ComScore for July 2009
This ComScore data shows that North America (more than just the US) represents 22.1% of worldwide search traffic. By this ratio, the Nielson US ranking divided by .22 would be 26.8 billion searches worldwide for Google if the US represented all of North America. If the US represents 50% of North America, then the Nielson data represents a worldwide number of 53.6 billion searches worldwide.

Worldwide Search Market Overview by Region
July 2009
Total Worldwide – Age 15+, Home/Work Locations
Source: comScore qSearch

  Searches (MM) Share (%) of Searches Search Usage Days Per Searcher Searches Per Searcher Worldwide 113,685 100.0% 11.0 103.3 Europe 36,446 32.1% 11.8 116.9 Asia Pacific 35,001 30.8% 9.3 84.7 North America 25,095 22.1% 12.5 110.6 Latin America 10,524 9.3% 13.0 130.4 Middle East - Africa 6,619 5.8% 10.5 97.3