GFR Calculator – Calculate Glomerular Filtration Rate | DietDekho
🩺 Free Health Tool

GFR Calculator
Glomerular Filtration Rate

Enter your lab results to instantly calculate your estimated Glomerular Filtration Rate (eGFR). Understand your kidney function and discover supportive, practical steps for better health.

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CKD-EPI2021 Method
100%Free Tool

Calculate Your GFR

Check your kidney function quickly and easily

Select your sex assigned at birth.

Your age in years (18 or older).

years
Please enter a valid age (18+).

Enter the value from your recent blood test.

mg/dL
Please enter a valid creatinine level.
Understanding the Math

What Is Glomerular Filtration Rate (GFR)?

Your Glomerular Filtration Rate (GFR) is the best overall indicator of how well your kidneys are functioning. Your kidneys contain tiny filters called glomeruli. This rate estimates how much blood passes through these filters every single minute.

Because taking an exact, direct measurement of GFR is complicated, medical professionals use an estimated GFR (eGFR). This calculator uses the most current and accurate formula—the CKD-EPI 2021 equation—which calculates your score using your age, biological sex, and serum creatinine levels from a routine blood test.

Understanding The Stages
CKD Stages Chart

How to Read Your eGFR Results

eGFR Level Stage Description Diet Focus
90 or higher Stage 1 Normal or high function Healthy, balanced diet; stay hydrated
60 to 89 Stage 2 Mildly decreased function Manage blood pressure; watch sodium
45 to 59 Stage 3a Mild to moderate decrease Consult a dietitian; monitor protein & salt
30 to 44 Stage 3b Moderate to severe decrease Strict monitoring of potassium & phosphorus
15 to 29 Stage 4 Severely decreased function Specialized renal diet required
Less than 15 Stage 5 Kidney failure Medical intervention (dialysis planning)
Key Health Metrics
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Serum Creatinine

Creatinine is a waste product from the normal breakdown of your muscles. Healthy kidneys filter it out. If your kidney function falls, creatinine levels in the blood rise.

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Age Factor

It is completely normal for GFR to naturally decline as we get older. The calculation adjusts for your age so you aren’t falsely alarmed by age-related changes.

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Sodium Intake

A diet high in salt raises blood pressure, which is one of the leading causes of kidney stress. Controlling sodium is the first practical step in any kidney care plan.

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Ongoing Monitoring

A single eGFR test doesn’t diagnose disease. Doctors look for a trend of a low GFR lasting for three months or longer to make a diagnosis of Chronic Kidney Disease (CKD).

Support Your Kidneys
Actionable Advice

How to Support Your Kidneys Through Diet & Habits

  • 1
    Ditch the Extra Salt — Think of salt as an unnecessary burden on your kidneys. Avoid adding extra table salt to your meals, skip the pickles and papads, and steer clear of heavily processed packaged foods.
  • 2
    Manage Your Blood Sugar & Pressure — High blood pressure and diabetes are the two biggest enemies of kidney health. Stick to your prescribed medications and eat a balanced diet to keep these numbers in a healthy range.
  • 3
    Eat the Right Amount of Protein — While protein is essential, eating massive amounts can overwork compromised kidneys. If your GFR is low, work with a dietitian to find the exact portion of dal, paneer, or chicken your body needs without causing strain.
  • 4
    Stay Hydrated, But Don’t Overdo It — Drinking enough water helps your kidneys clear sodium and toxins. However, if you are in the later stages of kidney disease, your doctor might actually restrict your fluid intake. Always follow your doctor’s advice.
  • 5
    Avoid Unnecessary Supplements — Many over-the-counter protein powders, painkillers (like NSAIDs), and herbal supplements can quietly damage the kidneys. Always consult your doctor before popping a new pill or powder.
FAQs

Common Questions About Glomerular Filtration Rate

What is a normal glomerular filtration rate? +
For most healthy adults, a normal eGFR is 90 or higher. If your score is between 60 and 89, it means you have mildly decreased kidney function, which might be completely normal depending on your age. A score below 60 for 3 or more months indicates Chronic Kidney Disease (CKD).
Can I raise my GFR level? +
Kidney damage is generally irreversible, so you can’t magically “cure” a low GFR. However, you can absolutely prevent it from dropping further by controlling your blood pressure, managing diabetes, stopping smoking, and eating a kidney-friendly diet.
Does this calculator use the new formula without race? +
Yes! This calculator uses the CKD-EPI 2021 equation. This is the newest standard recommended by the National Kidney Foundation and the American Society of Nephrology, which intentionally removes race as a variable for a more equitable and accurate estimation.
Why do you need my age and sex to calculate GFR? +
Creatinine comes from muscle breakdown. Because men typically have more muscle mass than women, and because we all naturally lose muscle mass as we age, the formula uses age and biological sex to accurately adjust what a “normal” creatinine level means for you.
Should I fast before a creatinine blood test? +
Generally, you don’t need to fast for a standard creatinine test. However, eating a large amount of cooked meat right before your test can temporarily spike creatinine levels. Follow your healthcare provider’s specific instructions for your lab work.
Medical Disclaimer: This GFR Calculator is provided for educational and informational purposes only. It is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always consult with a physician, nephrologist, or registered dietitian to interpret your lab results and before making any changes to your health regimen.