16 C.F.R. § 460.11
Rounding off R-values
R-values shown in labels, fact sheets, ads, or other promotional materials must be rounded to the nearest tenth. However, R-values of 10 or more may be rounded to the nearest whole number.
R-values shown in labels, fact sheets, ads, or other promotional materials must be rounded to the nearest tenth. However, R-values of 10 or more may be rounded to the nearest whole number.