Marilyn vos Savant has an IQ of 228.

(X)

Alan S. Kaufman, a psychology professor and author of IQ tests, writes in IQ Testing 101 that "Miss Savant was given an old version of the Stanford-Binet (Terman & Merrill 1937), which did, indeed, use the antiquated formula of MA/CA × 100. But in the test manual's norms, the Binet does not permit IQs to rise above 170 at any age, child or adult. As the authors of the old Binet stated: 'Beyond fifteen the mental ages are entirely artificial and are to be thought of as simply numerical scores.' (Terman & Merrill 1937). ...the psychologist who came up with an IQ of 228 committed an extrapolation of a misconception, thereby violating almost every rule imaginable concerning the meaning of IQs."[13] Savant has commented on reports mentioning varying IQ scores she was said to have obtained.[14]

The second test reported by Guinness was Hoeflin's Mega Test, taken in the mid 1980s. The Mega Test yields IQ standard scores obtained by multiplying the subject's normalized z-score, or the rarity of the raw test score, by a constant standard deviation and adding the product to 100, with Savant's raw score reported by Hoeflin to be 46 out of a possible 48, with a 5.4 z-score, and a standard deviation of 16, arriving at a 186 IQ. The Mega Test has been criticized by professional psychologists as improperly designed and scored, "nothing short of number pulverization".[15]

Yes, it is very rare to have 160 + IQ. No, the calculator does not return 0.

This calculator is set to mean of 100. Blacks have mean of 85. While some individuals like that may exist, it's extemely rare