Creatinine Clearance Calculator
Check your kidney function (GFR) instantly
Quick Answer
Creatinine clearance (CrCl) measures how well your kidneys filter waste. Normal: 90+ mL/min | Kidney disease: below 60 mL/min | Dialysis needed: below 15 mL/min
Formula: Cockcroft-Gault equation (most accurate for clinical use)
Related Calculators
Kidney Function FAQ
What is creatinine clearance and why does it matter?
Creatinine clearance (CrCl) measures how well your kidneys filter waste from blood. It's the most accurate test for kidney function (also called GFR - glomerular filtration rate). Normal: 90+ mL/min. Below 60 = chronic kidney disease. Below 15 = kidney failure (dialysis needed). Early detection prevents irreversible damage.
What causes high creatinine levels?
High creatinine = poor kidney function. Causes: diabetes (40% of kidney disease), high blood pressure (30%), dehydration, kidney stones, urinary blockage, muscle injury, certain medications (NSAIDs, ACE inhibitors), high-protein diet, intense exercise. If creatinine >1.3 (men) or >1.1 (women), see a doctor.
How can I improve my kidney function naturally?
Top 5 kidney-protective strategies: 1) Control blood pressure (<130/80 - most important), 2) Control blood sugar (<7% A1C if diabetic), 3) Limit protein to 0.8g/kg body weight, 4) Drink 8+ glasses water daily, 5) Avoid NSAIDs (ibuprofen, naproxen). These can slow or reverse early kidney disease.
At what creatinine level do I need dialysis?
Dialysis is usually needed when CrCl drops below 15 mL/min (Stage 5 kidney failure). Symptoms: severe fatigue, nausea, vomiting, confusion, shortness of breath, swelling. Some patients start dialysis at CrCl 10-15 if symptoms are severe. Kidney transplant is the best long-term solution.
What foods protect kidney function?
Kidney-friendly foods: leafy greens (not spinach), cauliflower, blueberries, red bell peppers, cabbage, garlic, onions, apples, cranberries, egg whites, fish. AVOID: processed meats, canned foods (high sodium), dairy (high phosphorus), bananas/oranges (high potassium if CrCl <60).
Can medications damage my kidneys?
YES! Kidney-toxic medications: NSAIDs (ibuprofen, naproxen - avoid if CrCl <60), antibiotics (gentamicin, vancomycin), contrast dye (for CT scans), ACE inhibitors (monitor closely), Lithium, Metformin (stop if CrCl <30). Always tell doctors your kidney function before new medications.
How often should I check kidney function?
Healthy adults: Every 1-2 years after age 50. Diabetes/high blood pressure: Every 6-12 months (kidney disease risk is 3-5x higher). Known kidney disease: Every 3-6 months. Test includes: serum creatinine, BUN, GFR, urine albumin. Early detection saves kidneys!
What's the difference between creatinine and BUN?
Creatinine = waste from muscle breakdown (most accurate kidney test). BUN (blood urea nitrogen) = waste from protein breakdown (affected by diet, hydration). Both measure kidney function but creatinine is more reliable. Normal BUN/Creatinine ratio: 10:1 to 20:1. Ratio >20 suggests dehydration or kidney issues.
Get Your FREE Kidney Protection Plan
Personalized meal plan to improve kidney function + slow chronic kidney disease. Lower creatinine naturally. Valued at $147 — yours FREE.
✓ Kidney-friendly meals ✓ Lower creatinine ✓ 18,000+ helped
This is not medical advice — talk to your doctor. The sections below are educational estimates only. This calculator does not diagnose kidney disease, does not interpret lab results, and does not recommend any treatment. Serum creatinine and creatinine clearance must be interpreted by a doctor in the context of your full health picture. Talk to your doctor before acting on any result.
What Is Creatinine Clearance? — Kidney Function Marker
Creatinine is a waste product generated by normal muscle breakdown. Your kidneys filter it out of your blood and excrete it in urine. Creatinine clearance (CrCl) measures how much creatinine your kidneys clear per minute, expressed in milliliters per minute (mL/min).
CrCl is used as an estimate of glomerular filtration rate (GFR), the standard marker of kidney function. A higher CrCl means your kidneys are filtering well. A lower CrCl means kidney function is reduced. This calculator estimates CrCl from your age, weight, sex, and serum creatinine using the Cockcroft-Gault equation.
It is important to understand that this is an estimate, not a direct measurement. A direct measurement requires a 24-hour urine collection. This calculator is educational only and does not replace clinical testing.
The Cockcroft-Gault Formula — Full Equation
This calculator uses the Cockcroft-Gault equation, a widely used formula for estimating creatinine clearance from simple inputs:
CrCl (mL/min) = ((140 - age) x weight in kg) / (72 x serum creatinine in mg/dL)
Multiply by 0.85 for women
The formula was published in 1976 and remains a standard method for estimating kidney function, especially for adjusting medication doses. It uses age, weight, and serum creatinine as inputs, with a correction factor of 0.85 for women because women generally have lower muscle mass than men of the same age and weight.
This calculator implements that formula. The result is an estimate and should not be used for self-diagnosis or treatment decisions.
How the Inputs Work: Age, Weight, Serum Creatinine
Each input in the Cockcroft-Gault formula plays a specific role:
| Input | Why it matters |
|---|---|
| Age | Kidney function naturally declines with age. The (140 - age) term reduces the estimate for older adults. |
| Weight (kg) | Creatinine is produced by muscle. Heavier people generally have more muscle, so the formula scales by weight. |
| Serum creatinine (mg/dL) | The waste product being cleared. Higher serum creatinine means the kidneys are filtering less, so it is in the denominator. |
| Sex (0.85 for women) | Women typically have less muscle mass than men of the same age and weight, so the estimate is reduced by 15%. |
You get serum creatinine from a standard blood test (BMP or CMP panel). Enter the value from your most recent lab report. If you do not have a recent serum creatinine value, you cannot use this calculator — talk to your doctor about getting a blood test.
What Results Mean: CKD Stage Context Table
The calculator maps your CrCl result to a chronic kidney disease (CKD) stage. These are general ranges used for staging:
| CrCl (mL/min) | Stage | What it means |
|---|---|---|
| 90 or higher | Stage 1 | Normal or high kidney function. Maintain healthy habits. |
| 60 to 89 | Stage 2 | Mildly decreased function. Common with aging. Monitor. |
| 30 to 59 | Stage 3 | Moderate kidney disease. See a doctor for a plan. |
| 15 to 29 | Stage 4 | Severe kidney disease. See a nephrologist soon. |
| Below 15 | Stage 5 | Kidney failure. Dialysis or transplant may be needed. |
CrCl estimated by Cockcroft-Gault and eGFR from your lab report (often calculated by CKD-EPI) are usually close but not identical. CrCl is traditionally used for drug dosing, while eGFR is used to stage CKD. Ask your doctor which applies to you.
Limitations: Muscle Mass, Hydration, and More
The Cockcroft-Gault formula is an estimate, not a direct measurement. It has important limitations you should know:
- Muscle mass — the formula assumes average muscle mass. Very muscular people can have a falsely low estimate; people with low muscle mass (elderly, frail, amputees) can have a falsely high estimate.
- Weight — the formula uses total body weight. For people with significant obesity, using actual weight can overestimate kidney function. Some clinicians use adjusted or ideal body weight instead.
- Hydration — dehydration can raise serum creatinine and lower the estimate. Rehydrate and retest if the result seems off.
- Diet — a very high meat intake can raise serum creatinine. A creatine supplement can also raise it. These do not reflect kidney damage.
- Medications — NSAIDs, some antibiotics, and other drugs can temporarily raise serum creatinine. Tell your doctor everything you take.
- Not a diagnosis — a single estimate does not diagnose kidney disease. Your doctor looks at trends over time, urine tests, and your full clinical picture.
For a direct measurement, a 24-hour urine collection for creatinine clearance is more accurate. For drug dosing, your pharmacist or doctor may use a different formula. This calculator is for education only.
Clinical Use Only: Talk to Your Doctor
This is not medical advice — talk to your doctor. This calculator is an educational tool that estimates creatinine clearance from body measurements and a lab value. It does not diagnose kidney disease, it does not determine whether you need dialysis, and it does not tell you whether a medication is safe for your kidneys.
- Do not change any medication based on this estimate. Some drugs are cleared by the kidneys and must be dose-adjusted by a doctor or pharmacist.
- Do not start or stop a diet, supplement, or treatment based on this estimate.
- Do not interpret a lab result yourself. Serum creatinine and CrCl must be read in context by a clinician.
- If your result is below 60 mL/min, or if you have symptoms like swelling, fatigue, or changes in urination, see a doctor.
- If you have diabetes or high blood pressure, ask your doctor how often to check kidney function.
This page is for general education. It is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your doctor with any questions about a medical condition.
Worked Example
A 55-year-old male enters 75 kg (about 165 lb) and a serum creatinine of 1.2 mg/dL from a recent blood test.
Calculation (Cockcroft-Gault)
CrCl = ((140 - 55) x 75) / (72 x 1.2)
CrCl = (85 x 75) / 86.4
CrCl = 6375 / 86.4
Result: CrCl = 73.8, rounded to 74 mL/min (Stage 2, mildly decreased)
A CrCl of 74 mL/min is in the mildly decreased range (Stage 2). This is common with aging and does not always mean kidney disease. A doctor would interpret this in context of other labs, blood pressure, and medical history. This is an estimate, not a diagnosis.
How to Use This Calculator & What to Do With Your Result
How to use it:
- Get a recent serum creatinine value from your blood test (BMP or CMP panel).
- Enter your age, sex, weight, and serum creatinine into the calculator above.
- Click calculate to see your estimated CrCl and CKD stage.
- Read the limitations section above before interpreting the result.
What to do with your result:
- If your result is 90 or higher, your kidney function estimate is in the normal range. Maintain healthy habits.
- If your result is 60 to 89, it is mildly decreased. Ask your doctor how often to recheck.
- If your result is below 60, bring it to your doctor. Do not self-treat.
- If you have diabetes or high blood pressure, ask about regular kidney screening.
- Remember the estimate is not a diagnosis. Only your doctor can interpret it in context.
Creatinine Clearance Calculator FAQs
Related Kidney & Health Calculators
Get a Personalized Plan
Tell our AI your goal — get a custom diet & macro plan in 60 seconds.
Upgrade to Premium
$9.99/month. Unlimited scans, food diary, meal plans. Cancel anytime.
No medical advice. For informational purposes only.
Scan Food, Get Instant Calories
Photo → Nutrition facts in 3 seconds. No typing, no guessing.
🧮 All 37 Free Calculators
See All →Top Features
📱 Free Mobile App
All 37 calculators + AI food scanner in one app