Combined eGFR stage (rows) × urine ACR stage (columns). Enter ACR in the Calculator to highlight your cell. Based on KDIGO 2012 guidelines.
Low risk
Moderately increased
High risk
Very high risk
Highest risk
Multi-Formula Comparison
eGFR Sensitivity to Creatinine Changes
How your eGFR changes with small variations in creatinine (current row highlighted).
Creatinine Change
eGFR (mL/min/1.73m²)
CKD Stage
Stage-Specific Clinical Guidance
Kidney Function Progress Tracker
Track creatinine over time to monitor eGFR trend. Uses the age & sex from the Calculator tab.
Date
Creatinine
eGFR
Stage
Change
How to Use This Calculator
1
Enter Lab Values
Input your serum creatinine, age, and biological sex from your lab report. Toggle µmol/L if your lab uses SI units. Add your ACR for full KDIGO risk classification.
2
Review Your Results
See your eGFR on the animated gauge, CKD stage, kidney function percentage, and KDIGO risk level. Check the Clinical Analysis tab for the risk heat map and dietary/medication guidance.
3
Track Over Time
Use the Progress Tracker to enter multiple creatinine measurements with dates. See a Chart.js trend line with CKD stage bands, calculate annual decline rate, and estimate time to next stage.
Published by Inker et al. (NEJM, 2021). Race-neutral equation recommended by ASN, NKF, and AHA. More accurate than MDRD at higher eGFR values. κ=0.7(F)/0.9(M), α=−0.241(F)/−0.302(M).
Developed by Levey et al. (1999). Less accurate at GFR >60 mL/min. Still used in some legacy laboratory systems. This calculator uses the race-neutral version.
Estimated Glomerular Filtration Rate — measures how much blood (mL) your kidneys filter per minute, normalized to 1.73m² body surface area. The gold standard for kidney function assessment.
Creatinine
A waste product of muscle metabolism filtered by the kidneys. Elevated levels indicate decreased kidney clearance. Affected by muscle mass, diet, hydration, and acute illness.
ACR (Albumin-Creatinine Ratio)
Measures albumin (protein) in urine relative to creatinine. A1 (<30 mg/g) = normal/mild; A2 (30–300 mg/g) = moderately increased; A3 (>300 mg/g) = severely increased. A key marker of kidney damage.
KDIGO
Kidney Disease: Improving Global Outcomes — the international organization that publishes CKD classification guidelines. The KDIGO risk grid combines eGFR and ACR categories into a 5-color risk classification.
CKD
Chronic Kidney Disease — defined as abnormalities of kidney structure or function (eGFR <60 or kidney damage markers) persisting for >3 months. Classified G1–G5 by eGFR and A1–A3 by albuminuria.
Real-World Examples
Example 1
Normal Kidney Function
Female, 45 years, Creatinine: 0.9 mg/dL, ACR: 12 mg/g
Monitor if other risk factors; lifestyle modification
G2
60–89
Mildly Decreased
Check UACR; manage risk factors annually
G3a
45–59
Mildly to Moderately Decreased
Every 6 months; consider nephrology referral
G3b
30–44
Moderately to Severely Decreased
Nephrology referral; prepare for RRT planning
G4
15–29
Severely Decreased
Active nephrology care; dialysis/transplant preparation
G5
<15
Kidney Failure
Kidney replacement therapy (dialysis or transplant)
Understanding Kidney Function and eGFR
What eGFR Tells You
eGFR estimates how efficiently your kidneys filter waste from the blood. A normal eGFR is above 90 mL/min/1.73m². Values below 60 persisting for 3+ months define chronic kidney disease (CKD). Early detection is critical because CKD often progresses silently until late stages.
The 2021 CKD-EPI Update
In 2021, the CKD-EPI equation was revised to remove the race coefficient, providing a single, race-neutral equation for all patients. This change — endorsed by the American Society of Nephrology — may reclassify some patients to earlier CKD stages, enabling earlier intervention and more equitable care worldwide.
KDIGO Risk Classification
The KDIGO 2012 guidelines introduced a combined risk framework using both eGFR and urine albumin. Albuminuria (protein in urine) is a direct marker of kidney damage, independent of eGFR. The famous colored heat map combines both factors into a comprehensive 5-level risk classification that guides monitoring frequency and referral decisions.
Protecting Your Kidneys
Control blood pressure (target <130/80 mmHg), manage diabetes (A1C <7%), stay well-hydrated, avoid chronic NSAID use, limit dietary sodium, and maintain a healthy weight. ACE inhibitors and ARBs have proven kidney-protective effects in diabetic and proteinuric kidney disease. These measures can slow CKD progression significantly.
Frequently Asked Questions
What is a normal eGFR level? +
A normal eGFR is 90 or above (Stage G1). Values of 60–89 indicate mild decrease (G2). Below 60 for 3+ months confirms CKD. Note: eGFR naturally declines about 1 mL/min/year after age 40, so an eGFR of 70–80 in a 70-year-old may be age-appropriate.
What is the difference between CKD-EPI and MDRD? +
CKD-EPI 2021 is the current standard — more accurate at eGFR above 60, uses no race coefficient, and is recommended by major nephrology societies. MDRD tends to underestimate eGFR at higher values (i.e., overcall kidney disease). For drug dosing, the Cockcroft-Gault formula is still preferred.
Can dehydration falsely lower my eGFR? +
Yes. Dehydration, illness, or strenuous exercise can temporarily raise creatinine and lower eGFR (pre-renal azotemia). This is reversible. CKD diagnosis requires findings to persist for 3+ months. If you had a low eGFR during illness, recheck when well and well-hydrated.
Does muscle mass affect eGFR accuracy? +
Yes. High muscle mass (bodybuilders, athletes) increases creatinine production, potentially lowering eGFR below true kidney function. Low muscle mass (elderly, sarcopenic individuals) may give falsely reassuring eGFR. Cystatin C-based eGFR is more accurate in these populations.
How often should I check my eGFR? +
G1–G2: annually if risk factors present (diabetes, hypertension, family history). G3a/G3b: every 6 months. G4: every 3 months. G5: as directed by nephrologist, often monthly. Anyone with diabetes or hypertension should have annual eGFR screening.