Well, slim to none, and I believe slim just left town. Unless, of course, your name is Marilyn vos Savant. Marilyn vos Savant is listed in the 1986 edition of The Guinness Book of World Records as having the highest recorded IQ in the world, with an IQ score of 228. She writes a weekly article in Parade magazine (usually included with the Sunday newspaper in many cities) entitled "Ask Marilyn," in which readers have been trying to stump the genius for many years, to no avail.
If you accurately want to learn what your IQ is (to see if you can compete with Marilyn), you will have to take one of the complicated tests, like the WISC or another in depth test. There are, however, a number of tests available on the Internet which provide a rough idea of what your IQ would be. Keep in mind that these do not have adequate sample sizes, have too few questions, and do not use verbal sections, making them far less accurate and usable than the standard tests. They are great for conversation, though. Do a Google for "IQ tests" to find some to try out.