Hello everyone,
I have been going through this since 2009, asking questions about the equivalence of HND In US, this and that, but unfortunately I couldn't find a reliable answer, till February 2012, and I thought of sharing it cos I believe other are out there like I was before.

First I would like to start by saying. YES!!!! NIGERIAN HND IS EQUIVALENT TO A US BACHELOR DEGREE. Am sure of what am saying because my HND transcripts (that's both my ND & HND) were evaluated as an American bachelors degree.

I would also like to tell you that working or getting admitted into American colleges is based on American qualifications and grades, so to work or get admission into American colleges, first try and get your certificate, diploma, degree or whatever you hold into American equivalence, and you can do that by sending your transcripts to one of the evaluation agencies, WES (world Education Services) http://www.wes.org/ is accepted by almost all American colleges but you can still find out more at http://www.naces.org/members.htm

For more guidelines on how to get to admission into American College with a HND a brother has helped out on his blog, and you can check it out here http://www.farooqkperogi.com/2009/12/hnd-and-american-universities.html and http://www.farooqkperogi.com/2009/03/looking-at-american-education-with_382.html

I would like to share my experience: I graduated with a HND in Electronics Engineering in 2009 from a Nigerian Federal Polytechnic, and sent my transcript to World Education Services WES on October 2011, I paid $202 for the service, the evaluation is supposed to be completed in 7days once all my documents are received, but we all know our 9ja na, considering the fact that the country was in crises it took me 3months to get my transcript to WES, again early JAN 2012 WES sent back another copy to FED POLY, for verification, and at the time our beloved nation is on strike due to subsidy matter and boko haram wahala, till 1st feb 2012, that's when WES got a feed back and my application became complete, on 8th Feb, 2012, my evaluation was complete.

I graduate in Nigeria with 3.14 out of 4.0 CGPA, which is of course our Upper Credit as we call it. But to my surprise from the evaluation my GPA was high to 3.56 out 4.0, that is based on the American System, moreover, in US they use a system of Credit Hours to determine your qualification, and in other to have a US bachelor degree, you must at-least have a minimum of 120 Credit Hours, but from my evaluation I had 135 Credit Hours, which is almost more-than that of the US. And as am typing this I have already applied to one of the top 15 engineering and technology university in the world for my masters program with a HND, and they have assured me that I would get it, after all am having a 3.56 GPA, and a good GRE score (GRE is an exams u sit for before applying for most graduate programs in US, its just like GMAT).
But still there are some few things you should be aware of, just because your transcripts are equivalent to a US degree, doesn't mean you will not take undergraduate courses, yes you will automatically be enrolled to a masters degree, as far as you meet the requirements, but there are some certain courses that you must take which of course are undergraduate courses, and the reason is because those courses are expected by all American graduates and in other to be one, you must go through it, such courses are like those related to the American policies, government, etc. (I haven't reached that stage, am just telling you based on what the school I applied for feed me too).

So to all those who keep asking, what is the equivalence of HND in US, its equivalent to a BACHELOR DEGREE but you really need to make good grades in your HND before you have something of worth, because I don't think there is any American University that would give you masters program with a minimum of 3.0GPA, U might get a provisional admission with a minimum of 2.5GPA (This is based on my reasoning, and what I have been going through, so just look out, cos I might be wrong)

If you need any proof regarding this, or guidelines don't hesitate to tell me or reply me, I promise i would help if I can, cos few years ago, I was once in the same point.

Cheers!