The FSIQ is determined by the sum of the scaled scores from the 10 subtests of the WISC (each subtest's scaled score can range from 1-19, higher if extended norms are used; the scaled scores are NOT the same as the composite scores that have a mean of 100). So, if you have the sum of scaled scores (or can calculate it if a tester provided the 10 subtest scaled scores) you may be able to figure out the FSIQ by looking for the same scaled score elsewhere on this board. Many people have posted WISC scores including both the sum of scaled scores and the corresponding FSIQ. So if you find a sum of scaled scores that matches yours, you have the FSIQ.
The following table won't be useful for 99.9% of the population, but the FSIQ equivalents using extended norms are available in the WISC Technical Report #7 (link below). Of course, these only apply to kids that needed the extended norms and have a sum of scaled scores greater than 167 (which corresponds to an FSIQ of 150 or higher), but just in case you are looking in that range, here is the link:
http://www.pearsonassessments.com/N...C-8E4A114F7E1F/0/WISCIV_TechReport_7.pdf
