GFR Calculator
GFR Calculator for Adults
This calculator is for people aged 18 years or older.
GFR Calculator for Children
This calculator is for people aged 18 years or younger.
Note: The GFR (glomerular filtration rate) Calculator estimates GFR values based on factors including serum creatinine value, age, race, and gender. For comparison purposes, the results for three prevalent formulas used for estimating GFR are provided.
These calculations are for educational purposes only and should not replace professional medical advice.
Glomerular Filtration Rate (GFR) Overview
GFR measures how well kidneys filter waste from blood, expressed in mL/min/1.73m². Higher values indicate better kidney function.
Key Facts:
- Normal Ranges:
- Men: 100-130 (under 40)
- Women: 90-120 (under 40)
- Declines with age (average 75 for 70+)
Chronic Kidney Disease Stages:
| Stage | GFR Range | Condition |
|---|---|---|
| Normal | 90+ | Healthy kidneys |
| CKD1 | 90+ | With kidney damage |
| CKD2 | 60-89 | Mild |
| CKD3 | 30-59 | Moderate |
| CKD4 | 15-29 | Severe |
| CKD5 | <15 | Kidney failure |
Measurement Methods:
- Gold Standard: Inulin clearance (precise but impractical)
- Clinical Standard: Creatinine-based estimates (easier but affected by muscle mass)
Common Estimation Formulas:
- MDRD Equation:
175 × (SCr)⁻¹·¹⁵⁴ × (age)⁻⁰·²⁰³ × (0.742 if female) × (1.212 if Black) - CKD-EPI Formula:
Varies by gender/race with different calculations above/below SCr thresholds - Mayo Formula:
e^(1.911 + 5.249/SCr - 2.114/SCr² - 0.00686×age - [0.205 if female]) - Pediatric (Schwartz):
0.413 × height(cm)/SCr
Clinical Notes:
- GFR >60 may still indicate CKD if declining
- Early detection helps prevent dialysis
- Regular monitoring recommended for at-risk patients
This version maintains all key information while being significantly more concise and visually organised for better readability. The tables and bullet points make the clinical data more accessible.