eGFR Calculator

eGFR estimates how efficiently your kidneys filter metabolic waste from the blood each minute, expressed in mL/min/1.73 m². A normal eGFR is 90 or above, indicating no significant impairment. Values between 60 and 89 indicate mildly decreased function (stage G2) — often normal for older adults due to the physiological decline of approximately 1 mL/min per year after age 40. Values below 60 persisting for three or more months confirm chronic kidney disease regardless of the cause. Early detection is clinically critical because CKD frequently progresses without symptoms until stages G4 or G5, when dialysis or transplant may be the only options. A single low eGFR reading does not confirm CKD — the KDIGO definition requires the finding to persist beyond three months. Temporary drops in eGFR are common after dehydration, illness, or nephrotoxic medications such as NSAIDs or contrast agents. Interpreting eGFR requires clinical context — a stable eGFR of 55 in an 80-year-old is very different from the same value in a 35-year-old.

The 2009 CKD-EPI equation included a race variable that added approximately 16% to the calculated eGFR for patients identified as Black, based on studies showing higher average muscle mass in that demographic. In 2021, a joint task force of the American Society of Nephrology and the National Kidney Foundation found that the race coefficient introduced systematic inequities — it delayed CKD diagnosis, reduced referral rates, and influenced drug dosing decisions in ways that harmed Black patients. The updated 2021 CKD-EPI equation was developed using the same underlying population data but removes the race variable entirely, producing a single equation applicable to all patients. The change means some patients previously calculated with the race coefficient will see their eGFR reclassified to an earlier CKD stage under the new formula. This is not a worsening of kidney function — it is a more equitable assessment. Most major US laboratories and clinical guidelines now use the race-neutral 2021 equation.

The KDIGO 2012 guidelines introduced a two-dimensional risk framework using both eGFR and urine albumin (measured as ACR). Albuminuria is a direct marker of kidney damage — protein leaking into the urine indicates that the glomerular filtration barrier is compromised, independent of how fast the kidneys are filtering. The KDIGO heat map plots eGFR category (G1–G5) against albuminuria category (A1–A3) to produce a combined risk level: low (green), moderately increased (yellow), high (orange), or very high (red/deep orange). A patient in G3a (eGFR 45–59) with A2 albuminuria (30–300 mg/g ACR) is classified as high risk, requiring monitoring every 6 months rather than annually. This combined framework explains why two patients with the same eGFR can have very different clinical trajectories and treatment urgency. Getting an ACR test alongside your creatinine enables the full KDIGO classification and gives your healthcare provider a far more complete picture of kidney health than eGFR alone. The ACR test requires only a urine sample and is widely available.

For people with existing CKD, several evidence-based interventions can slow or halt progression. Blood pressure control is the most important modifiable factor — KDIGO recommends a target below 120/80 mmHg in patients with albuminuria. ACE inhibitors and ARBs have proven kidney-protective effects in both diabetic and non-diabetic kidney disease by reducing intraglomerular pressure and decreasing proteinuria, and are first-line treatments for proteinuric CKD. For people with type 2 diabetes and CKD, SGLT2 inhibitors (empagliflozin, dapagliflozin) and GLP-1 agonists have demonstrated kidney-protective benefits beyond glucose control in major randomized trials. Dietary sodium restriction reduces blood pressure and proteinuria. Chronic NSAID use should be strictly avoided — even over-the-counter ibuprofen taken regularly reduces renal blood flow and can accelerate CKD progression over months. For people without existing kidney disease, staying well-hydrated, controlling blood pressure and blood glucose, and having annual creatinine testing if you have diabetes, hypertension, or a family history of kidney disease are the most impactful preventive strategies available.