IQ stands for "intelligence quotient" and is typically found by taking a standardized test that evaluates things such as language comprehension, visual perception, memory, quantitative reasoning and logical reasoning. There are many official IQ tests available, but the score is not considered to be "real" unless the test is administered by someone professionally qualified to do so. Even among official IQ tests, there are variations among resulting scores. Online tests are even less consistent, not standardized and not created or analyzed by qualified professionals, so there are no online IQ tests that will offer truly accurate results.
Find someone qualified to administer an IQ test. For children, schools with gifted programs may offer free testing for students and administer standardized IQ tests at the request of parents and/or guidance counselors. Adults can discover their score by contacting a licensed psychologist who is qualified to administer the test or by contacting an organization such as Mensa, which determines its membership based on official IQ scores.
Prepare for taking the test. As with any test, being well-rested, healthy and well-fed can help you relax and focus. Unlike achievement tests taken in school, IQ tests are not designed to test what is already learned, but instead evaluate how well your brain stores, processes and uses information, as compared to other people of the same age. You can take practice tests to become familiar with what an IQ test is like, but practice will have little influence on the results of the official IQ test.
Discuss what your results mean with the professional who has administered the test; an official IQ test administered by a professional compares your scores with thousands of other scores in your age and language group. Without these standardized tests comparing your age, language or other personal data scientifically by a professional, the results will have no meaning; this is why online tests do not accurately assess intelligence and only exist as entertainment.