What is a normal eGFR?

A normal eGFR is ≥90 mL/min/1.73m². However, eGFR naturally declines with age (~1 mL/min/year after 40). CKD is diagnosed when eGFR is <60 for 3+ months or kidney damage markers (albuminuria, abnormal imaging) are present.

What is a normal eGFR by age?

Healthy, disease-free adults have lower eGFR as they age: 20s ≈ 116, 30s ≈ 107, 40s ≈ 99, 50s ≈ 93, 60s ≈ 85, 70s ≈ 75, 80+ ≈ 66 mL/min/1.73m² (NHANES reference data). An 'abnormal' result must be judged against age — a 70-year-old with eGFR 72 is within the healthy range.

Is the CKD-EPI 2021 formula accurate?

The 2021 CKD-EPI equation is the current standard recommended by KDIGO. It is race-free and more accurate than older MDRD or Cockcroft-Gault equations, especially at higher GFR. Results within ±10-15% of measured GFR are expected.

Why was race removed from the eGFR equation?

The 2021 CKD-EPI equation removed the race coefficient because race is a social construct, not a biological variable, and its inclusion overestimated GFR in Black patients — delaying CKD diagnosis and care. KDIGO 2024 recommends the race-free equation for everyone.

What can affect my creatinine level?

Muscle mass, protein intake, creatine supplements, vigorous exercise, hydration, and some medications (trimethoprim, cimetidine, SGLT2 inhibitors' initial dip) affect serum creatinine. This is why repeated measurements over 3+ months confirm CKD.

Is eGFR in pregnancy different?

Yes — during pregnancy, true GFR rises ~40-50% but serum creatinine falls (lower muscle mass dilution and increased clearance), so creatinine-based eGFR equations are NOT reliable in pregnancy. eGFR is also inaccurate at extremes of body habitus and in severe muscle wasting.

Can I have kidney disease with a normal eGFR?

Yes. CKD can exist with eGFR ≥60 if there are kidney damage markers — especially albuminuria (UACR ≥30 mg/g), blood in urine, or abnormal imaging. That's why KDIGO stages by both eGFR (G) and albuminuria (A). Check the CKD stage checker with your UACR.

What if I have one kidney?

With one healthy kidney, eGFR can be ~50-75% of two-kidney function (often 60-85 mL/min/1.73m²) — that's expected and typically stable. You have ~2x reserve per nephron. Monitor eGFR and blood pressure yearly; protect the remaining kidney.

How is eGFR different from creatinine clearance (CrCl)?

eGFR (CKD-EPI) is indexed to body surface area (1.73 m²) and is best for staging. Creatinine clearance (Cockcroft-Gault) is a raw clearance in mL/min used in many drug labels for dosing. The two can differ by 20-30% — use the formula the drug label specifies.

What does 'eGFR >90' on my report mean?

It means estimated filtration is at or above 90 mL/min/1.73m² — normal. Lab reports cap eGFR at '>90' because CKD-EPI is not reliable above 90; if kidney damage markers are present, an accurate value matters for staging, which is why cystatin C may be added.

Kidney Function

eGFR Calculator (CKD-EPI 2021)

Estimate glomerular filtration rate and check your CKD stage. Updated 2026-08.

eGFR Calculator (CKD-EPI 2021)

Estimate glomerular filtration rate and check your CKD stage

Serum Creatinine(mg/dL)

Age(years)

Sex

Weight (for Cockcroft-Gault comparison)(kg)optional

Enter your values above to see the result (all fields required).

For education and screening only — not a substitute for professional medical assessment. Results should be interpreted by your healthcare provider.

Quick Answers: What Your Result Means

eGFR 90+Stage G1

Normal or high filtration — no CKD unless kidney damage markers are present.

Next: Recheck yearly if you have diabetes, hypertension, or family history.

eGFR 60-89Stage G2

Mildly reduced — common with aging; CKD only if damage markers (albuminuria) are present.

Next: Check urine albumin-creatinine ratio (UACR); control BP and blood sugar.

eGFR 45-59Stage G3a

Mild-moderate decrease — CKD confirmed if persistent 3+ months.

Next: Nephrology review; kidney-protective medications (SGLT2i, ACEi/ARB) discussion.

eGFR 30-44Stage G3b

Moderate-severe decrease — higher risk of progression and heart disease.

Next: Specialist follow-up every 3-6 months; check potassium, hemoglobin, phosphorus.

eGFR 15-29Stage G4

Severe decrease — kidney failure approaching.

Next: RRT education (dialysis, transplant), vascular access planning, anemia/bone management.

eGFR <15Stage G5

Kidney failure — dialysis or transplant usually needed.

Next: Urgent nephrology care; prepare for renal replacement therapy.

CKD-EPI 2021 vs MDRD vs Cockcroft-Gault

Three equations are commonly seen on lab reports and drug labels. CKD-EPI 2021 is now the standard for staging (KDIGO 2024): it is race-free and the most accurate across all GFR levels, particularly above 60. The MDRD equation (1999/2006) systematically underestimates GFR above 60 and was designed for people with known CKD. Cockcroft-Gault estimates creatinine clearance (not BSA-indexed GFR) using body weight — which is why drug labels still reference it for dosing.

This calculator shows all three side by side when you enter your weight, so you can compare the number on your lab report (usually CKD-EPI) with the clearance used in drug dosing.

CKD-EPI 2021 — race-free, recommended by KDIGO 2024 for diagnosis and staging.
MDRD — older; underestimates GFR when kidney function is near-normal.
Cockcroft-Gault — uses weight; used for medication dose adjustment (CrCl).

eGFR and medication safety

Many common drugs need dose adjustment or avoidance based on eGFR. This is one of the most important reasons kidney function is checked before prescribing.

Metformin: safe to start at eGFR ≥45; do not start at 30-45; stop below 30 (FDA 2016).
SGLT2 inhibitors (dapagliflozin, empagliflozin): kidney-protective in CKD; initiation thresholds eGFR ≥25 (dapagliflozin) and ≥20 (empagliflozin, CKD with albuminuria); stop at dialysis.
NSAIDs (ibuprofen, diclofenac, naproxen): avoid regular use in CKD — they reduce kidney blood flow, raise blood pressure, and blunt ACEi/ARB protection.
ACE inhibitors / ARBs: protective in CKD with albuminuria — continue; check potassium and creatinine 1-2 weeks after dose changes.
Anticoagulants (apixaban, rivaroxaban, dabigatran): dose adjusted or avoided at low eGFR/CrCl — see the drug dosing tool.

When to see a nephrologist (red flags)

Not every person with a mildly reduced eGFR needs a specialist. But these findings warrant a referral without delay:

eGFR below 30 mL/min/1.73m², or rapidly falling (more than 5 mL/min/yr, or 25% in one year)
Urine albumin-creatinine ratio above 300 mg/g (A3) at any eGFR
Blood in the urine (especially with red cell casts) or unexplained foamy urine
High potassium (above 5.5 mEq/L) or severe anemia (Hb <10 g/dL) with CKD
Uncontrolled blood pressure despite 3+ medications
Symptoms of uremia: nausea, loss of appetite, itching, swelling, fatigue

Normal eGFR by age (healthy adults, NHANES reference data)
Age	Mean eGFR (mL/min/1.73m²)	Lower normal bound
20-29	116	90
30-39	107	90
40-49	99	80
50-59	93	70
60-69	85	60
70-79	75	50
80+	66	40

NHANES reference population (Poggio ED et al., Am J Kidney Dis 2009)

Sources & References

KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of CKD
Inker LA et al. CKD-EPI 2021 race-free equation. NEJM 2021;385:1737-1749
Levey AS et al. MDRD study equation. Ann Intern Med 2006;145:247-254
FDA Metformin label update (2016)
Poggio ED et al. eGFR reference values. Am J Kidney Dis 2009;54:632-644

How to Use

1Enter the most recent serum creatinine result (mg/dL or µmol/L).
2Enter age and biological sex.
3Optional: enter weight to also see the Cockcroft-Gault clearance (used for drug dosing).
4The result includes your estimated GFR, corresponding KDIGO CKD stage, and MDRD comparison.

Understanding Results

Stage G1 — Normal (≥90)

Kidney function normal. Monitor yearly if risk factors (diabetes, hypertension) exist.

Stage G2 — Mildly decreased (60-89)

Mildly reduced. Manage risk factors; repeat testing as advised by your doctor.

Stage G3a — Mild-moderate (45-59)

CKD confirmed if persistent ≥3 months. Discuss kidney-protective therapy (SGLT2i etc.) with your nephrologist.

Stage G3b — Moderate-severe (30-44)

Moderate-severe CKD. Specialist follow-up, proteinuria check, and medication review needed.

Stage G4 — Severe (15-29)

Severe CKD. Prepare for renal replacement therapy education; monitor potassium and hemoglobin.

Stage G5 — Kidney failure (<15)

Kidney failure. Dialysis or transplant evaluation required. See your nephrologist urgently.

Frequently Asked Questions

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More Calculators

Creatinine Clearance (Cockcroft-Gault)

Estimate creatinine clearance for drug dosing

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CKD Stage Checker

Classify your CKD stage from eGFR and albuminuria

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Cystatin C eGFR (CKD-EPI 2012)

Confirm kidney function with a muscle-independent marker

Learn more

eGFR Decline Rate & Time-to-Failure Estimator

Measure how fast your kidney function is falling

Learn more

Explore related tools & guides

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Quick Answers: What Your Result Means

eGFR 90+Stage G1

Normal or high filtration — no CKD unless kidney damage markers are present.

Next: Recheck yearly if you have diabetes, hypertension, or family history.

eGFR 60-89Stage G2

Mildly reduced — common with aging; CKD only if damage markers (albuminuria) are present.

Next: Check urine albumin-creatinine ratio (UACR); control BP and blood sugar.

eGFR 45-59Stage G3a

Mild-moderate decrease — CKD confirmed if persistent 3+ months.

Next: Nephrology review; kidney-protective medications (SGLT2i, ACEi/ARB) discussion.

eGFR 30-44Stage G3b

Moderate-severe decrease — higher risk of progression and heart disease.

Next: Specialist follow-up every 3-6 months; check potassium, hemoglobin, phosphorus.

eGFR 15-29Stage G4

Severe decrease — kidney failure approaching.

Next: RRT education (dialysis, transplant), vascular access planning, anemia/bone management.

eGFR <15Stage G5

Kidney failure — dialysis or transplant usually needed.

Next: Urgent nephrology care; prepare for renal replacement therapy.

CKD-EPI 2021 vs MDRD vs Cockcroft-Gault

This calculator shows all three side by side when you enter your weight, so you can compare the number on your lab report (usually CKD-EPI) with the clearance used in drug dosing.

CKD-EPI 2021 — race-free, recommended by KDIGO 2024 for diagnosis and staging.

MDRD — older; underestimates GFR when kidney function is near-normal.

Cockcroft-Gault — uses weight; used for medication dose adjustment (CrCl).

eGFR and medication safety

Many common drugs need dose adjustment or avoidance based on eGFR. This is one of the most important reasons kidney function is checked before prescribing.

Metformin: safe to start at eGFR ≥45; do not start at 30-45; stop below 30 (FDA 2016).

SGLT2 inhibitors (dapagliflozin, empagliflozin): kidney-protective in CKD; initiation thresholds eGFR ≥25 (dapagliflozin) and ≥20 (empagliflozin, CKD with albuminuria); stop at dialysis.

NSAIDs (ibuprofen, diclofenac, naproxen): avoid regular use in CKD — they reduce kidney blood flow, raise blood pressure, and blunt ACEi/ARB protection.

ACE inhibitors / ARBs: protective in CKD with albuminuria — continue; check potassium and creatinine 1-2 weeks after dose changes.

Anticoagulants (apixaban, rivaroxaban, dabigatran): dose adjusted or avoided at low eGFR/CrCl — see the drug dosing tool.

When to see a nephrologist (red flags)

Not every person with a mildly reduced eGFR needs a specialist. But these findings warrant a referral without delay:

eGFR below 30 mL/min/1.73m², or rapidly falling (more than 5 mL/min/yr, or 25% in one year)

Urine albumin-creatinine ratio above 300 mg/g (A3) at any eGFR

Blood in the urine (especially with red cell casts) or unexplained foamy urine

High potassium (above 5.5 mEq/L) or severe anemia (Hb <10 g/dL) with CKD

Uncontrolled blood pressure despite 3+ medications

Symptoms of uremia: nausea, loss of appetite, itching, swelling, fatigue

Age

Mean eGFR (mL/min/1.73m²)

Lower normal bound

20-29

116

30-39

107

40-49

50-59

60-69

70-79

80+

eGFR Calculator (CKD-EPI 2021)

eGFR Calculator (CKD-EPI 2021)

Quick Answers: What Your Result Means

CKD-EPI 2021 vs MDRD vs Cockcroft-Gault

eGFR and medication safety

When to see a nephrologist (red flags)

Sources & References

How to Use

Understanding Results

Frequently Asked Questions

The Clinical OS for Dialysis Centers

More Calculators

Creatinine Clearance (Cockcroft-Gault)

CKD Stage Checker

Cystatin C eGFR (CKD-EPI 2012)

eGFR Decline Rate & Time-to-Failure Estimator

Explore related tools & guides

Educational information only

Sources and methodology

eGFR Calculator (CKD-EPI 2021)

eGFR Calculator (CKD-EPI 2021)

Quick Answers: What Your Result Means

CKD-EPI 2021 vs MDRD vs Cockcroft-Gault

eGFR and medication safety

When to see a nephrologist (red flags)

Sources & References

How to Use

Understanding Results

Frequently Asked Questions

The Clinical OS for Dialysis Centers

More Calculators

Creatinine Clearance (Cockcroft-Gault)

CKD Stage Checker

Cystatin C eGFR (CKD-EPI 2012)

eGFR Decline Rate & Time-to-Failure Estimator

Explore related tools & guides

Educational information only

Sources and methodology