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eGFR Calculator (CKD-EPI 2021, Race-Free)
eGFR (estimated glomerular filtration rate) is calculated from serum creatinine, age and sex with the CKD-EPI 2021 equation, which no longer uses race. A 50-year-old man with a creatinine of 1.0 mg/dL has an eGFR of about 92 mL/min/1.73 m², which falls in KDIGO category G1. Enter your values below for the result, the G category and the formula.
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The equation was built for adults (18 and over).
Use the standardized (IDMS-traceable) value from the lab report.
Estimated GFR (CKD-EPI 2021)
92mL/min/1.73 m²
KDIGO category G1: Normal or high (eGFR 90 or higher)
Category is by eGFR alone. Staging chronic kidney disease also needs albuminuria and how long the finding has lasted.
Decision support only; it does not replace clinical judgment. This is the published equation, not a diagnosis.
KDIGO GFR categories
| Category | eGFR (mL/min/1.73 m²) | Term |
|---|---|---|
| G1 (your result) | 90 or higher | Normal or high |
| G2 | 60 to 89 | Mildly decreased |
| G3a | 45 to 59 | Mildly to moderately decreased |
| G3b | 30 to 44 | Moderately to severely decreased |
| G4 | 15 to 29 | Severely decreased |
| G5 | Below 15 | Kidney failure |
The CKD-EPI 2021 eGFR formula
The 2021 CKD-EPI creatinine equation estimates GFR in mL/min per 1.73 m² of body surface area:
eGFR = 142 × min(Scr/κ, 1)α × max(Scr/κ, 1)−1.200 × 0.9938age × 1.012 [if female]
| Term | Female | Male |
|---|---|---|
| κ | 0.7 | 0.9 |
| α | −0.241 | −0.302 |
| Sex factor | × 1.012 | none |
Scr is standardized serum creatinine in mg/dL. If your lab reports µmol/L, divide by 88.4 first. The min and max terms mean one branch applies below the κ threshold and the other applies above it. There is no race term in this version.
Worked examples: eGFR calculation step by step
Man, 50, creatinine 1.0 mg/dL. Scr/κ = 1.0 ÷ 0.9 = 1.111, which is above 1, so the max term applies: 1.111−1.200 = 0.881. The age term is 0.993850 = 0.733. eGFR = 142 × 0.881 × 0.733 = 91.7, rounded to 92. That is category G1.
Woman, 60, creatinine 1.2 mg/dL. Scr/κ = 1.2 ÷ 0.7 = 1.714. 1.714−1.200 = 0.523, 0.993860 = 0.688, and the sex factor is 1.012. eGFR = 142 × 0.523 × 0.688 × 1.012 = 51.8, rounded to 52. That is category G3a.
Man, 70, creatinine 2.5 mg/dL. The same steps give an eGFR of 27, category G4.
Rounded values are shown for readability. The calculator keeps full precision internally.
KDIGO GFR categories (G1 to G5)
| Category | eGFR | Term |
|---|---|---|
| G1 | 90 or higher | Normal or high |
| G2 | 60 to 89 | Mildly decreased |
| G3a | 45 to 59 | Mildly to moderately decreased |
| G3b | 30 to 44 | Moderately to severely decreased |
| G4 | 15 to 29 | Severely decreased |
| G5 | Below 15 | Kidney failure |
These are the bands in the KDIGO 2024 chronic kidney disease guideline and on the National Kidney Foundation staging page. They describe the eGFR number only. KDIGO also grades albuminuria (A1 to A3), and a CKD diagnosis depends on how long the finding has persisted. This page does not make that determination.
eGFR and creatinine clearance: which number is which
A lab report may show an eGFR, a creatinine clearance, or both. The eGFR here is indexed to 1.73 m². Creatinine clearance from Cockcroft-Gault uses the patient's weight and is not indexed. Use the creatinine clearance calculator when your protocol asks for CrCl, and the LDL calculator or A1c calculator for other lab math.
Practices that run weight-management, hormone or IV programs often keep recent labs next to the visit note. Prospyr's charting keeps notes and chart documents with the patient record; see the med spa software page for how the rest of the practice fits around it.
Frequently asked questions
What is the formula for eGFR?
The CKD-EPI 2021 creatinine equation is eGFR = 142 × min(Scr/κ, 1)^α × max(Scr/κ, 1)^−1.200 × 0.9938^age × 1.012 if female. Scr is serum creatinine in mg/dL, κ is 0.7 for women and 0.9 for men, and α is −0.241 for women and −0.302 for men. The National Kidney Foundation publishes the same equation.
Does the eGFR calculator still use race?
No. The 2021 CKD-EPI creatinine equation was developed without a race coefficient, as described by Inker and colleagues in the New England Journal of Medicine in 2021. This calculator asks only for age, sex and creatinine.
How do I convert creatinine from µmol/L to mg/dL?
Divide µmol/L by 88.4 to get mg/dL. A creatinine of 88.4 µmol/L is 1.0 mg/dL. The calculator does this for you when you switch units, and it shows the converted value in the formula line.
What do the eGFR stages G1 to G5 mean?
KDIGO groups eGFR into G1 (90 or higher, normal or high), G2 (60 to 89, mildly decreased), G3a (45 to 59), G3b (30 to 44), G4 (15 to 29, severely decreased) and G5 (below 15, kidney failure). The categories describe the number only. Staging chronic kidney disease also takes albuminuria and duration into account.
What is a normal eGFR by age?
KDIGO labels an eGFR of 90 or higher as normal or high, and 60 to 89 as mildly decreased. Because the equation includes age, the same creatinine gives a lower eGFR as age rises. This tool reports the published category and does not say what is normal for an individual patient.
What is the difference between eGFR and creatinine clearance?
eGFR comes from the CKD-EPI equation and is standardized to 1.73 m² of body surface area. Creatinine clearance comes from the Cockcroft-Gault equation, uses actual weight and is reported in mL/min. They are different estimates and can disagree, so use the one your protocol names. Our creatinine clearance calculator covers Cockcroft-Gault.
Can this tell me whether a patient has kidney disease?
No. It calculates the published equation and shows the published category. A diagnosis of chronic kidney disease depends on repeat results, albuminuria and clinical context, and that judgment belongs to the treating provider.
Sources and scope
- Inker LA et al. New Creatinine- and Cystatin C-Based Equations to Estimate GFR without Race. N Engl J Med 2021;385:1737-49
Peer-reviewed. The CKD-EPI 2021 equations, developed without a race coefficient.
- National Kidney Foundation: CKD-EPI Creatinine Equation (2021)
The equation with κ, α, the 0.9938 age term and the 1.012 female factor, as used here.
- National Kidney Foundation: How to classify CKD
GFR categories G1 to G5 and albuminuria categories A1 to A3.
- KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney Int 2024
Guideline that defines the G-stage bands. This tool quotes the bands, not the treatment recommendations.
Decision support only; it does not replace clinical judgment. The tool applies the published equation and quotes the published category. It does not diagnose, stage disease on its own, or recommend treatment, drug doses or clearance for a procedure.