The NAEP provides ethnic averages and percentiles in both reading and math for 8th graders in 2019. I chose 8th graders because they are the oldest age group for which they have nationally representative samples, since 12th graders only include those who have not yet dropped out of school. Note: scores are reported on 0 to 500 scale.
whites | blacks | Hispanics | American Indian/Alaska native | Asian/Pacific Islander | Multiracial | |
90th percentil | 314 | 288 | 297 | 293 | 326 | 312 |
Average | 272 | 244 | 252 | 248 | 281 | 267 |
10th percentile | 227 | 197 | 202 | 198 | 232 | 218 |
Estimated SD | 34 | 36 | 38 | 38 | 37 | 37 |
whites | blacks | Hispanics | American Indian/Alaska native | Asian/Pacific Islander | Multiracial | |
90th percentil | 339 | 306 | 314 | 308 | 364 | 337 |
Average | 292 | 260 | 268 | 262 | 310 | 286 |
10th percentile | 245 | 215 | 222 | 215 | 252 | 235 |
Estimated SD | 37 | 36 | 36 | 37 | 44 | 40 |
Although the NAEP is not an IQ test, the correlation between IQ tests and scholastic achievement tests is about as high as the correlation between two IQ tests, making them statistically equivalent in the general population. Further, the main reason people care about racial IQ gaps is because they translate into racial learning gaps, so converting to IQ seems appropriate and the advantage of using the NAEP to infer group IQ gaps is the excellent sampling this data has among subjects who have spent their whole lives learning these skills.
reading IQ | math IQ | composite IQ | |
whites | 100 | 100 | 100 |
blacks | 88 | 88 | 86 |
Hispanics | 91 | 90 | 90 |
American Indian/Alaska native | 89 | 88 | 88 |
Asian/Pacific Islander | 104 | 107 | 106 |
Multiracial | 98 | 98 | 97 |
For technical details on how these scores were converted to IQ, see technical note below.
Technical note
The reading, math, and composite NAEP scores were converted to IQ by equating the white NAEP means with 100 and the white NAEP SDs with 15. The reading and math SDs were estimated by subtracting the 90th percentile NAEP scores from the 10th percentile scores and dividing by 2.53 (the bell curve Z score difference between these percentiles) .To determine the white mean of the composite score, we simply add the reading and math means, which gives 564. The white SD of the composite score was crudely estimated by assuming the reading and math correlation among all white 8th graders taking the NAEP is the same as the correlation among all college bound 17-year-olds taking the SAT (r = 0.67 according to Herrnstein and Murray). Using the formula for calculating the composite SD (from page 779 of the book The Bell Curve by Herrnstein and Murray):

This gives a composite white SD of 65.