GFR/eGFR Calculator

Estimate glomerular filtration rate using the CKD-EPI creatinine equation.

About GFR/eGFR Calculator

The 2021 CKD-EPI equation removed the race coefficient present in earlier versions. GFR categories describe filtration but do not by themselves establish chronic kidney disease, which also requires persistence and other markers. Creatinine depends on muscle mass, so estimates are less reliable at extremes of body composition, where cystatin C based equations are preferred.

Formula

GFR/eGFR

CKD-EPI 2021: 142 × min(Scr/κ,1)^α × max(Scr/κ,1)^−1.209 × 0.9938^age × sex factor

CKD-EPI 2021: The current race-free creatinine equation
1.73 m²: GFR is indexed to standard body surface area

Worked example

With the default values below, GFR/eGFR Calculator returns Estimated GFR of 86.99. Change any input above and every figure here is recalculated in your browser.

Inputs used

Serum creatinineminimum 1 umol/L: 90 umol/L
Ageaccepts 18–110 years: 55 years
Sexone of Male, Female: Male

Results

Estimated GFR: 86.99 mL/min/1.73m2
CKD Stage by GFR Category: G2, mildly decreased
Serum Creatinine: 1.018 mg/dL
Share of a Typical Young Adult GFR: 72.5%
Interpretation: A GFR category alone does not establish chronic kidney disease without other markers

Step by step

1Values used
2GFR/eGFR
3Estimated GFR= 86.99 mL/min/1.73m2
4CKD Stage by GFR Category= G2, mildly decreased
5Serum Creatinine= 1.018 mg/dL
6Share of a Typical Young Adult GFR= 72.5
7Interpretation= A GFR category alone does not establish chronic kidney disease without other markers

Assumptions and limits

The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
This reproduces a published formula for educational and reference use only. It is not a diagnostic tool, does not account for individual clinical context, and must not be used to make or change treatment decisions. Clinical assessment by a qualified healthcare professional is always required. eGFR is an estimate that becomes unreliable in acute illness, pregnancy, extremes of body composition and with certain medicines. Drug dosing based on renal function must follow specific prescribing guidance.
This is an estimate for general information and not professional medical advice. See the full disclaimer for the limits that apply to this kind of calculator.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

This reproduces a published formula for educational and reference use only. It is not a diagnostic tool, does not account for individual clinical context, and must not be used to make or change treatment decisions. Clinical assessment by a qualified healthcare professional is always required. eGFR is an estimate that becomes unreliable in acute illness, pregnancy, extremes of body composition and with certain medicines. Drug dosing based on renal function must follow specific prescribing guidance.

Frequently Asked Questions

How is GFR/eGFR calculated?

CKD-EPI 2021: 142 × min(Scr/κ,1)^α × max(Scr/κ,1)^−1.209 × 0.9938^age × sex factor The 2021 CKD-EPI equation removed the race coefficient present in earlier versions. GFR categories describe filtration but do not by themselves establish chronic kidney disease, which also requires persistence and other markers.

Why does GFR/eGFR matter?

Creatinine depends on muscle mass, so estimates are less reliable at extremes of body composition, where cystatin C based equations are preferred.

What values do I need to enter?

This calculator takes 3 inputs: Serum creatinine, Age, Sex. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.