Calculating ΔR from a marine sample whose year of collection is known involves 2 steps:

1. Intersect the calendar year of collection with the marine calibration curve and determine the corresponding ¹⁴C age (reverse-calibrate).
2. Subtract the reverse-calibrated collection year from the mean of the ¹⁴C age of the marine sample

The uncertainty of ΔR is the uncertainty of the marine sample ¹⁴C measurement