RADIOCARBON TO CALENDAR DATE CONVERSION - CALENDRICAL BAND WIDTHS AS A FUNCTION OF RADIOCARBON PRECISION

Accurate high-precision C-14 dating (i.e., +/- 20 yr precision or less on the C-14 date) provides the narrowest calendrical band width and, hence, the best age range determination possible. However, because of the structure in the C-14 calibration curve, the calendar age range for a given C-14 precision is not constant throughout the calibration range. In this study, we quantify the calendar band widths for a range of C-14 precisions throughout the calibration range. We show that an estimate of the likely calendar band width in years can be obtained from the expression: Band width (yr) = 2.12 x C-14 precision (1 sigma) + 54.6. We also show that calendar band widths are widest around 4000 BP at the start of the Bronze Age, and become narrow through the later Bronze Age and Iron Age and back into the Neolithic.