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eGFR Calculator (Kidney Function)

Estimate Glomerular Filtration Rate using CKD-EPI 2021 (race-free) for adults. CKD stage classification + KDIGO reference.

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eGFR Calculator (Kidney Function)

Generated on April 25, 2026

For adults (≥18 years). Uses the CKD-EPI 2021 race-free formula — the current National Kidney Foundation / ASN recommendation. eGFR is reported in mL/min/1.73 m² (already body-surface-area normalized — don't multiply again).

Typical adult: 0.6-1.3 mg/dL (53-115 µmol/L).

G1 — Normal
95 mL/min/1.73 m²

Normal kidney function (with kidney damage marker for CKD diagnosis).

Kidney function gauge

95mL/min/1.73m²012060

CKD stage scale (KDIGO)

G1 — Normal≥ 90
G2 — Mild60-89
G3a — Mild-moderate45-59
G3b — Moderate-severe30-44
G4 — Severe15-29
G5 — Kidney failure0-14

Step-by-step calculation

Formula

CKD-EPI 2021 (race-free): eGFR = 142 × min(Scr/κ, 1)^α × max(Scr/κ, 1)^−1.2 × 0.9938^age × (1.012 if female). κ = 0.9 (M) or 0.7 (F). α = −0.302 (M) or −0.241 (F).

  1. 1Serum creatinine: 1.0 mg/dL.
  2. 2Age: 45 years, sex: male.
  3. 3κ (kappa) = 0.9, α (alpha) = −0.302.
  4. 4eGFR = 142 × min(1.000/0.9, 1)^−0.302 × max(1.000/0.9, 1)^−1.2 × 0.9938^45.
  5. 5= 94.59 mL/min/1.73 m² → G1 — Normal.
  6. 6KDIGO stage definitions: G1 ≥90, G2 60-89, G3a 45-59, G3b 30-44, G4 15-29, G5 <15.
For diagnosis CKD requires eGFR < 60 OR a marker of kidney damage (proteinuria, abnormal imaging, biopsy) for ≥ 3 months. eGFR alone isn't a CKD diagnosis. Single measurements vary ±15%; trends over multiple measurements matter more than any single value. Always discuss results with a doctor.

?What is the eGFR Calculator (Kidney Function)?

The eGFR (estimated Glomerular Filtration Rate) Calculator estimates kidney function from serum creatinine, age, and sex using the CKD-EPI 2021 formula — the current National Kidney Foundation / American Society of Nephrology recommendation, replacing older race-adjusted equations. Reports eGFR in mL/min/1.73 m² (already body-surface-area normalized) and classifies into KDIGO Chronic Kidney Disease stages G1-G5. Used by every nephrology clinic in the world; an essential check for diabetes, hypertension, and pre-medication safety.

The Formula

CKD-EPI 2021: eGFR = 142 × min(Scr/κ, 1)^α × max(Scr/κ, 1)^−1.2 × 0.9938^age × (1.012 if female). κ=0.9(M)/0.7(F), α=−0.302(M)/−0.241(F). Scr in mg/dL.

The 'race-free' update in 2021 removed the controversial race coefficient that systematically over-estimated kidney function in Black patients (delaying transplant referrals). The new formula uses only creatinine, age, and sex — evidence-based and equitable. eGFR is reported per 1.73 m² (body-surface-area normalized) so values are comparable across body sizes. KDIGO stages: G1 ≥90, G2 60-89, G3a 45-59, G3b 30-44, G4 15-29, G5 <15.

Practical Examples

1

Healthy 30-year-old male, creatinine 1.0 mg/dL: eGFR ≈ 105 mL/min/1.73 m² (G1, normal).

2

Healthy 65-year-old female, creatinine 0.9 mg/dL: eGFR ≈ 70 (G2, age-related decline — likely normal).

3

Diabetic 60-year-old male, creatinine 1.7 mg/dL: eGFR ≈ 47 (G3a, beginning CKD).

4

Creatinine 2.5 mg/dL in a 50-year-old female: eGFR ≈ 22 (G4, severe — needs nephrology referral).

5

Creatinine 6.0 mg/dL: eGFR ≈ 9 (G5, kidney failure — dialysis or transplant required).

Frequently Asked Questions

Because creatinine production depends on muscle mass — a 65 kg woman with creatinine 1.0 has worse kidney function than a 90 kg man with the same number. eGFR adjusts for age and sex (proxies for muscle mass) to give a fairer comparison.

Popular Conversions

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