estimated Glomerular Filtration Rate (eGFR; units mL/min/1.73m2) is often used in practice for determining renal function since it is readily available via lab results. It should be adjusted for body surface area in individuals with extremes of size. Alternatively, the Cockcroft-Gault formula (CrCl) can be used.
For more background information, see:
– recent MHRA article. Note they refer to eGFR as the reported lab value (mL/min/1.73m2) rather than adjusting for the individual patient’s body surface area.