I know the variable NUMPREC tells you the number of person records associated with a household. Is this the same as the number of individuals in the household/ household size? There is also a variable NUMPERHH which reports how many people lived within the household but it does not seem to be available in the 2015-2022 ACS 1 percent PUM set. I was able to access the NUMPREC data. Does NUMPREC function as the number of individuals in the household?
In the ACS, NUMPREC is equivalent to the number of people in the household. NUMPERHH is available in IPUMS USA data from 1850-1950, and reports how many persons lived within the household. This number is sometimes larger than NUMPREC (the number of person records following the household record in the IPUMS), because the census PUMS from 1850 to 1930 did not sample large households (i.e., households containing more than 30 persons) in their entirety. Discrepancies between NUMPREC and the number of individuals in a household are not present in data from after 1930. NUMPREC is constructed by IPUMS, and simply counts the number of person records in each household. You can use NUMPREC as a measure of household size when working with ACS data (or any IPUMS USA data from 1940 and later).