Enter Patient Data
Formula Used
1) 2021 CKD-EPI creatinine eGFR: This adult equation estimates kidney filtration using age, sex, and standardized serum creatinine.
2) 2021 CKD-EPI creatinine-cystatin C eGFR: When cystatin C is available, the combined estimate is displayed as the primary eGFR.
3) Cockcroft-Gault creatinine clearance: This estimates drug-dosing clearance in mL/min using age, sex, serum creatinine, and the selected body-weight basis.
4) Mosteller body surface area: BSA = √((height in cm × weight in kg) ÷ 3600). Absolute eGFR is normalized eGFR × BSA ÷ 1.73.
5) CKD interpretation: G-stage uses eGFR bands, while A-stage uses urine albumin-to-creatinine ratio when available.
How to Use This Calculator
- Enter adult age, sex, serum creatinine, height, and weight.
- Select the creatinine unit that matches the lab report.
- Add cystatin C if available for a combined eGFR estimate.
- Add urine ACR to classify albuminuria and kidney risk.
- Choose the weight basis for Cockcroft-Gault clearance.
- Press calculate to view kidney estimates, stage, risk, exports, and the comparison chart.
Example Data Table
| Profile | Age | Sex | Creatinine | Cystatin C | ACR | Combined eGFR | Stage |
|---|---|---|---|---|---|---|---|
| Example A | 34 | Female | 0.78 mg/dL | 0.88 mg/L | 12 mg/g | 99.65 mL/min/1.73 m² | G1 / A1 |
| Example B | 58 | Male | 1.34 mg/dL | 1.42 mg/L | 120 mg/g | 55.46 mL/min/1.73 m² | G3a / A2 |
| Example C | 72 | Female | 2.10 mg/dL | 2.20 mg/L | 520 mg/g | 24.57 mL/min/1.73 m² | G4 / A3 |
These sample rows are illustrative and are generated with the same equations used by the calculator.
Frequently Asked Questions
1. What does eGFR mean?
eGFR estimates how much blood the kidneys filter each minute after normalization to 1.73 m² of body surface area. It is widely used for kidney staging and follow-up.
2. Why does the calculator ask for cystatin C?
Cystatin C can improve filtration estimates when creatinine alone may be misleading. When entered, the calculator shows the combined creatinine-cystatin C estimate as the primary displayed eGFR.
3. What is the difference between eGFR and Cockcroft-Gault?
eGFR is commonly used for CKD staging. Cockcroft-Gault estimates creatinine clearance in mL/min and is still referenced in many medicine-dosing workflows.
4. Why is height included?
Height helps estimate body surface area, ideal body weight, and adjusted body weight. Those values support absolute eGFR and the selected Cockcroft-Gault weight method.
5. Does one low result confirm chronic kidney disease?
No. Chronic kidney disease usually requires persistent abnormalities over time or other markers of kidney damage. A single result should be interpreted with the full clinical picture.
6. What does urine ACR add?
Urine albumin-to-creatinine ratio helps classify albuminuria as A1, A2, or A3. This improves risk interpretation beyond eGFR alone.
7. Is this calculator suitable for children?
No. This page is designed for adults because it uses adult estimating equations. Pediatric kidney estimation uses different methods.
8. Can I use this page for medicine dosing?
It can support review, especially with Cockcroft-Gault and absolute eGFR, but final dosing decisions should always follow the drug label and a clinician’s judgment.