# GFR Calculator

Gentian GFR Calculator v2.1

This tool calculates relative GFR from your Gentian Cystatin C value and absolute GFR using three parameters: Relative GFR, height and weight.

The calculation of the Absolute GFR below is based on the Du Bois and Du Bois^{1)} formula for body surface estimation.

To calculate relative GFR, insert cystatin c value and click the 'Relative GFR' button.

To calculate absolute GFR, insert relative GFR (or calculate from cystatin c value). Insert height and weight and click the 'Absolute GFR' button.

1) DuBois D and DuBois EF. A formula to estimate the approximate surface area if height and weight are known. Arch Intern Medicine. 1916; 17:863-871.