Enter Kidney Function Values
Formula Used
2021 CKD-EPI Creatinine Equation
eGFR = 142 × min(Scr / κ, 1)α × max(Scr / κ, 1)-1.200 × 0.9938Age × 1.012 if female.
- Scr means standardized serum creatinine in mg/dL.
- κ is 0.7 for females and 0.9 for males.
- α is -0.241 for females and -0.302 for males.
- Creatinine in µmol/L is converted by dividing by 88.4.
- eGFR SI conversion: mL/min/1.73 m² × 0.0167 = mL/s/1.73 m².
Cockcroft-Gault Creatinine Clearance
CrCl = ((140 - age) × weight in kg) / (72 × Scr). Multiply by 0.85 for females. This gives a creatinine clearance estimate in mL/min.
Body Surface Area Adjustment
BSA = 0.007184 × height0.725 × weight0.425. Absolute GFR = indexed eGFR × BSA / 1.73.
How to Use This Calculator
- Enter adult age in years.
- Select male or female because the equation uses sex factors.
- Enter serum creatinine from a laboratory report.
- Select the correct creatinine unit.
- Enter weight to calculate creatinine clearance.
- Add height when you need BSA and absolute GFR.
- Add urine ACR when available.
- Press the calculate button and review the result above the form.
- Use CSV or PDF buttons to save the result.
This tool is for educational use. Do not diagnose kidney disease or change treatment from this calculator alone.
Example Data Table
| Age | Sex | Creatinine | Weight | Approx eGFR | Stage |
|---|---|---|---|---|---|
| 35 | Female | 0.80 mg/dL | 62 kg | 101.90 | G1 |
| 50 | Male | 1.20 mg/dL | 78 kg | 73.16 | G2 |
| 68 | Female | 1.60 mg/dL | 70 kg | 34.75 | G3b |
| 74 | Male | 2.40 mg/dL | 82 kg | 27.25 | G4 |
About This Kidney Function Calculator
Kidney function is often reviewed with an estimated filtration value. This value is called eGFR. It helps describe how well the kidneys filter blood. The result is not a diagnosis by itself. It should be compared with symptoms, urine albumin, medicines, and repeat laboratory tests. It can also support patient education before an appointment. Clear records make later discussions easier and more focused. Bring exported notes to professional visits too.
This calculator uses adult inputs. It accepts age, sex, serum creatinine, weight, height, and albumin ratio. The tool can convert creatinine from micromoles per liter to milligrams per deciliter. It also converts weight and height when needed. These options reduce manual steps and help avoid unit mistakes.
Why eGFR Matters
The eGFR result is commonly grouped into G stages. Higher values usually show stronger filtration. Lower values may suggest reduced kidney function. A value below 60 can be important when it remains low for three months or more. Albumin in urine can also show kidney damage, even when filtration looks normal.
The calculator also shows Cockcroft-Gault creatinine clearance. This estimate uses age, weight, sex, and creatinine. It is different from eGFR. Some drug dosing decisions may still reference creatinine clearance. Always follow the method requested by a clinician, pharmacist, or laboratory report.
Using Results Safely
Enter values from a recent lab report. Check the creatinine unit before calculating. Add weight and height when you want body surface area details. Review the stage note and albumin category together. Do not change medicines based only on this page.
Many factors can affect creatinine. Muscle mass, hydration, pregnancy, diet, supplements, and acute illness may change the estimate. Children need different formulas. Older adults may need careful interpretation. A clinician can decide whether another test, such as cystatin C, urine albumin, imaging, or referral, is needed.
Export and Record Keeping
The CSV button saves a simple table for spreadsheets. The PDF button saves a clean summary for records. Keeping dates with results can help track trends. Trend review is often more useful than a single number. Use this calculator as an educational support tool, not as personal medical advice.
FAQs
What does this kidney function calculator estimate?
It estimates adult eGFR from creatinine, age, and sex. It also shows creatinine clearance, kidney stage, unit conversions, albumin category, and optional body surface area details.
Can this calculator diagnose kidney disease?
No. A diagnosis needs clinical review. A low result may need repeat testing, urine checks, symptoms review, medicines review, imaging, or specialist input.
Which creatinine unit should I select?
Select the unit printed on your lab report. Many reports use mg/dL. Some countries use µmol/L. The calculator converts µmol/L to mg/dL automatically.
Why does sex affect the result?
The adult equation uses different κ and α values for males and females. These factors help estimate filtration from creatinine more accurately.
What is creatinine clearance?
Creatinine clearance is another kidney function estimate. This page calculates it with the Cockcroft-Gault equation using age, weight, sex, and creatinine.
Why add urine albumin ratio?
Albumin ratio adds kidney damage context. A person may have normal filtration but increased urine albumin. Both values help risk review.
Can children use this calculator?
No. This page is designed for adults. Children need pediatric equations and professional interpretation based on age, size, and lab method.
Are the CSV and PDF files medical records?
They are simple exported summaries. They can support record keeping, but they should not replace official laboratory reports or clinical notes.