I'm subscribed to a lot of mailing lists - PHP, mod_perl, MySQL, web application security, etc. This week, there was an interesting conversation on the NYPHP mailing list - consulting rates.

It all started with an email from Edward Potter. He had previously emailed the list to inquire about consulting rates and was sharing the results with everyone:

Just to keep everyone up to date, based on interviews to date, the going rate for a 6 month contract with someone with a solid PHP/developer background/graduate degree in IT right now seems to top out at $60/hour based on a 6 month contract.

To be clear, he's suggesting that a good developer with a graduate degree can expect to charge a consulting rate of $60/hour at best. I tried to put this into perspective in my reply:

Doing some math in reverse:

$60 / 2.4 = $25
$25/hour = $50,000/year

Therefore, $60/hour as a consultant is roughly equivalent to $50,000/year as a full-time employee with benefits.

A few people questioned the 2.4 factor, and although I've seen plenty of references to this value (even in SLOCCount's cost estimating feature, something Zak has discussed), I was unable to find a definitive source for it, nor do I know what it's called. Anyone know? I have been using it to calculate rates for a few years.

What do you think the average salary is (or should be) for a good developer?