What is my creatinine clearance?
Calculate creatinine clearance rate to assess kidney function. Medical diagnostic calculator.
- Kidney function
- 92
With the 2021 CKD-EPI (recommended) formula, the result is 92 (eGFR, mL/min/1.73 m²), category G1: normal or high.
G1: normal or high
- G5: kidney failure
- G4: severely decreased
- G3b: moderately to severely decreased
- G3a: mildly to moderately decreased
- G2: mildly decreased
- G1: normal or high
- What this number is
- eGFR, mL/min/1.73 m²
- KDIGO GFR category
- G1: normal or high
Kidney function: 92. With the 2021 CKD-EPI (recommended) formula, the result is 92 (eGFR, mL/min/1.73 m²), category G1: normal or high.
Which GFR category?
This calculator gives general information only. It is not medical advice and does not replace a doctor or other health care provider. Talk with a professional about your results. Terms of use
How to calculate
Estimates kidney function from serum creatinine with the 2021 CKD-EPI equation (eGFR), the MDRD Study equation, or Cockcroft-Gault creatinine clearance, with the KDIGO GFR category.
Example with the default inputs (Formula 2021 CKD-EPI (recommended), Serum creatinine 1 mg/dL, Age 50, Sex Male): With the 2021 CKD-EPI (recommended) formula, the result is 92 (eGFR, mL/min/1.73 m²), category G1: normal or high.
Method: CKD-EPI 2021: 142 × min(Scr/κ, 1)^α × max(Scr/κ, 1)^−1.200 × 0.9938^age × 1.012 (women); MDRD: 175 × Scr^−1.154 × age^−0.203 × 0.742 (women) × 1.212 (Black); Cockcroft-Gault: (140 − age) × weight ÷ (72 × Scr) × 0.85 (women). Scr in mg/dL, weight in kg.
- Creatinine is IDMS-standardized (the MDRD constant 175 assumes this). µmol/L is converted with the creatinine molar mass 113.12 g/mol (1 mg/dL = 88.40 µmol/L).
- CKD-EPI and MDRD give eGFR per 1.73 m² of body surface area. Cockcroft-Gault gives creatinine clearance in mL/min, with actual body weight unless you read the ideal or adjusted rows.
- The categories are the KDIGO 2012 GFR categories. A category of chronic kidney disease also needs the value to last 3 months or more.
- For adults 18 and older with stable creatinine.
Worked examples
Each example is checked against the calculator on every build.
- Formula 2021 CKD-EPI (recommended), Serum creatinine 1 mg/dL, Age 50, Sex Male gives Kidney function 91.691479, KDIGO GFR category G1: normal or high.Source: Inker et al. (2021) CKD-EPI: 142 × (1.0/0.9)^−1.200 × 0.9938^50 = 91.69 mL/min/1.73 m²
- Formula 2021 CKD-EPI (recommended), Serum creatinine 0.6 mg/dL, Age 30, Sex Female gives Kidney function 123.757864, KDIGO GFR category G1: normal or high.Source: Inker et al. (2021) CKD-EPI: 142 × (0.6/0.7)^−0.241 × 0.9938^30 × 1.012 = 123.76
- Formula MDRD Study (older), Serum creatinine 2 mg/dL, Age 60, Sex Female, Black race (MDRD only) no gives Kidney function 25.414913, KDIGO GFR category G4: severely decreased.Source: Levey et al. (2006) MDRD: 175 × 2.0^−1.154 × 60^−0.203 × 0.742 = 25.41
- Formula Cockcroft-Gault (drug dosing), Serum creatinine 1.2 mg/dL, Age 60, Sex Female, Weight 65 kg, Height 165 cm gives Kidney function 51.157407, Ideal body weight 56.9 kg, Clearance with ideal weight 44.789844, Clearance with adjusted weight 47.336869.Source: Cockcroft and Gault (1976): (140 − 60) × 65 ÷ (72 × 1.2) × 0.85 = 51.16 mL/min
- Formula 2021 CKD-EPI (recommended), Serum creatinine 1.5 mg/dL, Age 70, Sex Male gives Kidney function 49.774777, KDIGO GFR category G3a: mildly to moderately decreased.Source: Inker et al. (2021) CKD-EPI: 132.6 µmol/L × 113.12 g/mol = 1.49997 mg/dL
How the result is worked out
Scr is serum creatinine in mg/dL. A value in µmol/L is converted with the molar mass of creatinine, C4H7N3O = 113.12 g/mol (IUPAC atomic weights), so 1 mg/dL = 88.40 µmol/L. Age is in whole years.
2021 CKD-EPI (the default)
eGFR = 142 × min(Scr/κ, 1)^α × max(Scr/κ, 1)^−1.200 × 0.9938^age × 1.012 (if female)
- κ = 0.7 for women, 0.9 for men
- α = −0.241 for women, −0.302 for men
- The result is in mL/min/1.73 m². The equation does not use race.
MDRD Study (4-variable, IDMS-standardized creatinine)
eGFR = 175 × Scr^−1.154 × age^−0.203 × 0.742 (if female) × 1.212 (if Black)
The result is in mL/min/1.73 m². The race factor is shown only for this older equation.
Cockcroft-Gault
Creatinine clearance = (140 − age) × weight ÷ (72 × Scr) × 0.85 (if female)
- Weight is actual body weight in kg, as in the 1976 paper. The result is in mL/min and is not adjusted to body surface area.
- If you enter height, the calculator also shows two common variants: with ideal body weight (Devine: 50 kg for men or 45.5 kg for women, plus 2.3 kg per inch of height over 5 feet) and with adjusted body weight (ideal + 0.4 × (actual − ideal)). Below 5 feet the same line continues: 2.3 kg is taken off for each inch under 5 feet. If that gives an ideal weight of 0 kg or less, the calculator shows neither variant.
GFR categories (KDIGO 2012)
The category is read from the result, lower bound included: G1 90 or more, G2 60 to under 90, G3a 45 to under 60, G3b 30 to under 45, G4 15 to under 30, G5 under 15. For Cockcroft-Gault the same cut-offs are applied to creatinine clearance, which is only an approximation of GFR.
Assumptions
- Adults 18 and older with stable kidney function.
- Values are not rounded between steps. The page shows whole numbers.
Worked examples by hand
Man, 50, creatinine 1.0 mg/dL (CKD-EPI). Scr/κ = 1.0 ÷ 0.9 = 1.1111, so the min term is 1 and the max term is 1.1111^−1.200 = 0.88123. 0.9938^50 = 0.73274. eGFR = 142 × 0.88123 × 0.73274 = 91.69, category G1.
Woman, 30, creatinine 0.6 mg/dL (CKD-EPI). Scr/κ = 0.6 ÷ 0.7 = 0.85714, so the min term is 0.85714^−0.241 = 1.03785 and the max term is 1. 0.9938^30 = 0.82979. eGFR = 142 × 1.03785 × 0.82979 × 1.012 = 123.76, G1.
Woman, 60, creatinine 2.0 mg/dL (MDRD, not Black). 175 × 2.0^−1.154 × 60^−0.203 × 0.742 = 175 × 0.44938 × 0.43555 × 0.742 = 25.41, G4.
Woman, 60, 65 kg, 165 cm, creatinine 1.2 mg/dL (Cockcroft-Gault). (140 − 60) × 65 ÷ (72 × 1.2) × 0.85 = 5,200 ÷ 86.4 × 0.85 = 51.16 mL/min. 165 cm = 64.961 in, so ideal weight = 45.5 + 2.3 × 4.961 = 56.91 kg, and clearance with it is 80 × 56.91 ÷ 86.4 × 0.85 = 44.79 mL/min. Adjusted weight = 56.91 + 0.4 × (65 − 56.91) = 60.15 kg, giving 47.34 mL/min.
Man, 70, creatinine 132.6 µmol/L (CKD-EPI). 132.6 µmol/L × 113.12 g/mol = 15.000 mg/L = 1.49997 mg/dL. Scr/κ = 1.66663; max term = 1.66663^−1.200 = 0.54174; 0.9938^70 = 0.64704. eGFR = 142 × 0.54174 × 0.64704 = 49.77, G3a.
Understanding Your Kidney Health
Learn about your kidneys, how they work, and what your test results mean for your overall health.
Your Kidneys: The Body's Master Filters
Think of your kidneys as the body's sophisticated, non-stop purification system. These two bean-shaped organs work around the clock to filter all the blood in your body. They remove waste products, toxins, and excess fluid, which they turn into urine to be expelled from the body. This vital filtering process helps control blood pressure, maintain a healthy balance of water and minerals, and produce hormones that keep your bones strong and your blood healthy.
What Is Creatinine and Why Do We Measure It?
Creatinine is a normal waste product that your body creates every day. It comes from the natural wear and tear on your muscles and from the creatine your body uses to produce energy.
Under normal circumstances, your healthy kidneys have no trouble filtering this creatinine out of your blood and sending it out of the body in your urine. However, if kidney function declines, they become less efficient at this filtering job. As a result, creatinine can start to build up in the bloodstream. By measuring the level of creatinine in a simple blood test, doctors can get a valuable snapshot of how well your kidneys are performing their filtering duties.
Understanding Your Kidney Numbers: From Creatinine to eGFR
While a serum creatinine level is a useful starting point, it doesn't tell the whole story. The amount of creatinine a person produces can vary significantly based on their age, biological sex, and muscle mass. For example, a muscular young man will naturally have a higher creatinine level than a frail elderly woman, even if both have perfectly healthy kidneys.
To get a more accurate and personalized assessment of kidney function, healthcare professionals use the estimated Glomerular Filtration Rate (eGFR). The eGFR is widely considered the best overall measure of kidney health. It is not a direct measurement but a calculation that uses your serum creatinine level along with your age and sex. The result provides a more complete picture of how many milliliters of blood your kidneys are filtering each minute, which is often interpreted as the percentage of kidney function you have.
What Your eGFR Result Means: The Stages of Kidney Health
Your eGFR result helps your doctor understand your kidney health and classify it into one of the KDIGO GFR categories below (G1 to G5; a chronic kidney disease stage also needs the result to last 3 months or more). In the early stages, the goal is to protect your kidneys and slow down any further damage.
Stage 1
eGFR 90 or higher
Normal or high kidney function. There might be other signs of kidney damage, like protein in the urine, even though the filtering rate is normal.
Stage 2
eGFR 60-89
Mild loss of kidney function. The goal is to manage underlying conditions like blood pressure and diabetes to protect the kidneys.
Stage 3a
eGFR 45-59
Mild to moderate loss of kidney function. Waste products can begin to build up in the body.
Stage 3b
eGFR 30-44
Moderate to severe loss of kidney function. With treatment and healthy lifestyle changes, many people can prevent progression.
Stage 4
eGFR 15-29
Severe loss of kidney function. It is the last stage before kidney failure, and planning for potential future treatments becomes important.
Stage 5
eGFR less than 15
Kidney failure (End-Stage Renal Disease). Treatments like dialysis or a kidney transplant are necessary to sustain life.
Factors That Can Affect Your Creatinine and eGFR Results
It's important to know that several factors can temporarily influence your creatinine level, and therefore your eGFR result. This does not necessarily mean your kidney function has changed. Discussing these factors with your doctor can help put your results in the proper context.
Factors that may temporarily increase creatinine:
- Diet: Eating large amounts of protein, especially cooked red meat, can briefly raise creatinine levels.
- Supplements: Taking creatine supplements, popular among athletes, will increase blood creatinine.
- Exercise: Intense, strenuous exercise can cause a temporary spike.
- Dehydration: Not drinking enough fluids can concentrate creatinine in the blood.
- Medications: Certain drugs, including some antibiotics and stomach acid blockers, can affect how your kidneys handle creatinine.
Factors that may be associated with lower creatinine:
- Low Muscle Mass: Since creatinine comes from muscle, individuals with lower muscle mass may have naturally lower levels.
- Diet: A long-term vegetarian or vegan diet may be associated with lower creatinine levels.
- Pregnancy: Increased blood flow to the kidneys during pregnancy often leads to lower creatinine levels.
- Liver Disease: Severe liver problems can impair the production of creatine, leading to lower creatinine.
A Vital Disclaimer: This Calculator Is an Educational Tool
The results provided by this calculator are an estimate and are intended for informational and educational purposes only. This tool is not a substitute for professional medical advice, diagnosis, or treatment.
Your eGFR value can be influenced by many factors, and lab results can vary. The formula used here may differ from the one used by your doctor's laboratory. You must consult a qualified healthcare professional to interpret any results and to make decisions about your health, diet, or treatment plan. Never disregard professional medical advice or delay in seeking it because of something you have read or calculated here.
Other questions people ask
What is creatinine clearance and why is it important?
Creatinine clearance is a measure of how well your kidneys are filtering waste from your blood. Creatinine is a waste product produced by your muscles and filtered out by your kidneys. If your kidneys aren't working properly, creatinine builds up in your blood. This test helps doctors assess kidney function and detect early signs of kidney disease.
What is a normal eGFR range?
A normal eGFR (estimated Glomerular Filtration Rate) is typically 90 mL/min/1.73m² or higher. Values between 60-89 may indicate mild kidney function loss, while values below 60 for 3 months or more suggest chronic kidney disease. However, eGFR naturally declines with age, so your doctor will interpret results in the context of your age and overall health.
What should I do if my eGFR is low?
The single most important step is to share and discuss this result with your doctor or another qualified healthcare provider. They can confirm the result with their own tests, investigate the cause of any potential issues, and work with you to create a health plan. It is critical that you do not make any changes to your diet, lifestyle, or medications based solely on the result from this or any other online calculator.
Can diet and exercise improve my kidney function?
While existing kidney damage usually cannot be reversed, a healthy lifestyle is absolutely essential for protecting your remaining kidney function and slowing the progression of any disease. Key strategies include managing blood pressure and blood sugar, eating a balanced, kidney-friendly diet (which may involve reducing animal protein, sodium, and sugar), staying well-hydrated, and avoiding overuse of certain medications like NSAID pain relievers. Always work with your doctor or a registered dietitian to develop a plan that is safe and effective for your specific situation.
Why does the calculator need my age and biological sex?
The amount of creatinine your body produces is directly related to your muscle mass, which naturally varies with age and typically differs between biological sexes. By including your age and sex in the calculation, the eGFR formula can provide a much more accurate and personalized estimate of your kidney function than looking at the creatinine blood level alone.
What is the difference between "Creatinine Clearance" and "eGFR"?
"Creatinine Clearance" (CrCl) is an older method of estimating kidney function. It was either calculated using the Cockcroft-Gault formula or directly measured with a cumbersome 24-hour urine collection process. "eGFR" (estimated Glomerular Filtration Rate) is the modern standard. It is calculated using a more accurate formula (like the 2021 CKD-EPI equation) from a simple blood test. For assessing overall kidney function, eGFR is now considered the more reliable and accurate measure. This calculator gives eGFR by default, and Cockcroft-Gault creatinine clearance when you pick it.
What is the 2021 CKD-EPI Creatinine Equation?
The 2021 CKD-EPI Creatinine Equation is the most current and recommended formula for estimating glomerular filtration rate (eGFR). It was developed by the Chronic Kidney Disease Epidemiology Collaboration and removes race-based variables to improve equity in care. The National Kidney Foundation recommends it for estimating GFR in adults.
Why are there warnings for older formulas?
Older formulas like MDRD and Cockcroft-Gault have limitations that make them less reliable for modern clinical use. The MDRD equation included race-based variables that have been removed from current guidelines. The Cockcroft-Gault formula (1976) was developed before modern laboratory standards and can overestimate kidney function, potentially leading to incorrect medication dosing decisions.
What do the CKD stages mean?
Chronic Kidney Disease (CKD) stages classify kidney function based on eGFR values. KDIGO names the GFR categories G1 to G5. G1 (90 or more) is normal or high, with possible signs of kidney damage. G2 (60-89) is mildly decreased. G3a (45-59) is mildly to moderately decreased and G3b (30-44) moderately to severely decreased. G4 (15-29) is severely decreased, and G5 (under 15) is kidney failure, which may need dialysis or a transplant.
When should I use the Cockcroft-Gault formula?
The Cockcroft-Gault formula is primarily used for medication dosing adjustments in patients with kidney disease, particularly for drugs that are renally eliminated. However, it should be used with caution as it can overestimate kidney function. The 2021 CKD-EPI equation is preferred for general kidney function assessment and CKD staging.
What units should I use for creatinine?
This calculator accepts both mg/dL (common in the US) and µmol/L (common internationally); for µmol/L, type the unit after the number, for example 88 µmol/L. The calculator converts µmol/L to mg/dL with the molar mass of creatinine (113.12 g/mol), so 1 mg/dL is 88.40 µmol/L. Use the units that match your laboratory results for the most accurate calculation.
How accurate are these calculations?
The 2021 CKD-EPI equation works well for most adults with stable kidney function. However, these are estimates and should be interpreted in clinical context. Factors like muscle mass, diet, medications, and acute illness can affect creatinine levels and eGFR accuracy. Always consult with healthcare professionals for clinical decisions.
Can I use this calculator for children?
No, this calculator is designed for adults (age 18 and older). The formulas used are validated for adult populations. Pediatric kidney function assessment requires different equations that account for age-related changes in muscle mass and body composition. Consult with pediatric nephrology for children's kidney function assessment.
What factors can affect my creatinine levels?
Creatinine levels can be influenced by muscle mass, diet (especially meat consumption), medications (like trimethoprim, cimetidine), dehydration, and acute illness. High muscle mass can increase creatinine without indicating kidney disease, while low muscle mass can mask kidney dysfunction. This is why eGFR calculations include age and sex variables.
How often should I check my kidney function?
The frequency depends on your health status and risk factors, such as diabetes, high blood pressure, a family history of kidney disease, or known CKD. Follow your healthcare provider's recommendations for monitoring frequency.