Calculator Inputs
Use this page for adults only. It supports screening and education, not diagnosis, emergency decisions, dialysis management, or pediatric assessment.
Example Data Table
| Age | Sex | Creatinine | Weight | Height | BUN | uACR | Expected Pattern |
|---|---|---|---|---|---|---|---|
| 52 | Male | 1.20 mg/dL | 78 kg | 172 cm | 18 mg/dL | 26 mg/g | Mild reduction absent; albumin normal |
| 67 | Female | 1.60 mg/dL | 64 kg | 160 cm | 34 mg/dL | 145 mg/g | Reduced eGFR with moderate albuminuria |
| 74 | Male | 2.70 mg/dL | 71 kg | 168 cm | 49 mg/dL | 420 mg/g | Advanced impairment with severe albuminuria |
Formula Used
1) eGFR using CKD-EPI 2021 creatinine equation
eGFR = 142 × min(Scr/K, 1)α × max(Scr/K, 1)-1.200 × 0.9938Age × 1.012 if female
K = 0.7 for females and 0.9 for males. α = -0.241 for females and -0.302 for males.
2) Cockcroft-Gault creatinine clearance
CrCl = ((140 - age) × weight in kg) / (72 × serum creatinine in mg/dL)
Multiply the result by 0.85 for females.
3) Body surface area and de-indexed eGFR
BSA = √((height in cm × weight in kg) / 3600)
De-indexed eGFR = eGFR × BSA / 1.73
4) Supporting checks
BUN/Creatinine ratio = BUN / serum creatinine
uACR categories: A1 under 30, A2 from 30 to 300, A3 above 300 mg/g.
How to Use This Calculator
1. Enter age, sex, serum creatinine, weight, and height.
2. Add BUN to estimate the BUN/creatinine ratio.
3. Add urine ACR for KDIGO albumin staging and risk mapping.
4. Submit the form and review the result cards above the form.
5. Use the table and graph to compare filtration, clearance, and risk bands.
6. Export the output using the CSV or PDF buttons for documentation or discussion.
Frequently Asked Questions
1) What does this calculator estimate?
It estimates adult kidney function using serum creatinine, then adds creatinine clearance, body-surface adjustment, BUN ratio, albumin category, and a simple risk summary.
2) Is eGFR the same as creatinine clearance?
No. eGFR is standardized to body surface area. Cockcroft-Gault creatinine clearance estimates unindexed clearance and is often reviewed during medicine dosing decisions.
3) Why is urine ACR optional?
The page still calculates filtration without it, but albuminuria is important for CKD staging and prognosis. Entering uACR gives a fuller kidney risk picture.
4) Can one result diagnose chronic kidney disease?
No. Chronic kidney disease usually requires persistent abnormalities for at least three months or other evidence of kidney damage confirmed clinically.
5) Why is height included?
Height helps estimate body surface area. That allows a de-indexed eGFR value, which can be useful when body-size adjustment matters during clearance review.
6) Does a high BUN/creatinine ratio prove dehydration?
No. It is only a pattern check. Diet, bleeding, catabolism, medicines, and kidney perfusion can also influence the ratio.
7) Can this be used for children?
No. This file is designed for adults. Pediatric kidney estimation uses different validated equations and clinical interpretation rules.
8) Should medicine doses be changed from this page alone?
No. Dose changes should follow the specific product label, the clinical context, and clinician review, especially near cutoff values.