(U–Th)/He chronology relies on accurate measurements of zircon grain dimensions, but the systematic error and uncertainty associated with those measurements have been unquantified until now. We build on the work of Zeigler et al. (2023) and present the zircon Geometric Correction Method, a simple solution to correcting the error and quantifying the geometric uncertainty in eU and dates. Including this geometric correction and uncertainty matters for data evaluation and interpretation.