Does eGFR replace 24-hour urine collection?

For most cases, yes — and thank goodness, because 24-hour urine collection is genuinely miserable. It's still technically the gold standard for creatinine clearance, but it's burdensome and error-prone (people forget collections, miss the timing). eGFR from a single blood draw correlates highly enough for clinical use except in unusual cases — extreme body composition, rapidly changing function.

Below what eGFR is dialysis needed?

Generally below 15 (Stage G5), though many patients start dialysis at 10 to 12 once symptoms develop. Some patients never need dialysis if their eGFR stabilizes at 15 to 20 with conservative management. The decision is made by your nephrologist based on the combination of symptoms, lab trends, and quality of life — there's no single magic number that triggers it automatically.

Can eGFR be too HIGH?

The reported eGFR is capped at 142 by the formula. Truly elevated filtration rate (hyperfiltration) can occur in early diabetes, pregnancy, after a high-protein meal, or in someone with a solitary kidney — but it isn't directly visible from the capped number alone. Persistent hyperfiltration eventually damages kidneys, which is why early diabetes management matters so much.

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eGFR Calculator (Kidney Function)

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Estimate Glomerular Filtration Rate using CKD-EPI 2021 (race-free) for adults. CKD stage classification + KDIGO reference.

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eGFR Calculator (Kidney Function)

Generated on May 23, 2026

For adults (≥18 years). Uses the CKD-EPI 2021 race-free formula — the current National Kidney Foundation / ASN recommendation. eGFR is reported in mL/min/1.73 m² (already body-surface-area normalized — don't multiply again).

Serum creatinine

Typical adult: 0.6-1.3 mg/dL (53-115 µmol/L).

Age (years)

Sex

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eGFR Result

eGFR 95 mL/min/1.73 m² — G1 — Normal

Generated

5/23/2026

G1 — Normal

95 mL/min/1.73 m²

Normal kidney function (with kidney damage marker for CKD diagnosis).

Kidney function gauge

CKD stage scale (KDIGO)

G1 — Normal≥ 90Normal kidney function (with kidney damage marker for CKD diagnosis).

G2 — Mild60-89Mildly decreased function. Still considered normal for many older adults.

G3a — Mild-moderate45-59Beginning of clinically significant CKD. Adjust some medication doses.

G3b — Moderate-severe30-44More significant decline. See nephrologist; manage cardiovascular risk.

G4 — Severe15-29Severe decline. Prepare for renal replacement therapy (dialysis or transplant).

G5 — Kidney failure0-14Kidney failure. Dialysis or transplant typically needed.

Step-by-step calculation

Formula

CKD-EPI 2021 (race-free): eGFR = 142 × min(Scr/κ, 1)^α × max(Scr/κ, 1)^−1.2 × 0.9938^age × (1.012 if female). κ = 0.9 (M) or 0.7 (F). α = −0.302 (M) or −0.241 (F).

1Serum creatinine: 1.0 mg/dL.
2Age: 45 years, sex: male.
3κ (kappa) = 0.9, α (alpha) = −0.302.
4eGFR = 142 × min(1.000/0.9, 1)^−0.302 × max(1.000/0.9, 1)^−1.2 × 0.9938^45.
5= 94.59 mL/min/1.73 m² → G1 — Normal.
6KDIGO stage definitions: G1 ≥90, G2 60-89, G3a 45-59, G3b 30-44, G4 15-29, G5 <15.

For diagnosis CKD requires eGFR < 60 OR a marker of kidney damage (proteinuria, abnormal imaging, biopsy) for ≥ 3 months. eGFR alone isn't a CKD diagnosis. Single measurements vary ±15%; trends over multiple measurements matter more than any single value. Always discuss results with a doctor.

Quick Answer

Estimate Glomerular Filtration Rate using CKD-EPI 2021 (race-free) for adults. CKD stage classification + KDIGO reference.

Overview — eGFR Calculator (Kidney Function)

Health

Formula

CKD-EPI 2021: eGFR = 142 × min(Scr/κ, 1)^α × max(Scr/κ, 1)^−1.2 × 0.9938^age × (1.012 if female). κ=0.9(M)/0.7(F), α=−0.302(M)/−0.241(F). Scr in mg/dL.

By Muhammad Salman SaleemUpdated: May 23, 2026MethodologyFree, no sign-upRuns in your browser — your data stays private

From the editors — what to know before you start

If you're here, the doctor probably said something that landed hard — 'your kidney function is low' or 'your eGFR is in stage 3'. You went home, opened a search, and ended up here trying to decode what the number actually means. Breathe. eGFR (estimated glomerular filtration rate) is the standard way doctors measure how well your kidneys are filtering blood, and it's calculated from your serum creatinine, age, and sex using the CKD-EPI 2021 formula — the current National Kidney Foundation recommendation that replaced older race-adjusted equations. Why race was removed in 2021 matters: the old formula added 21 percent to Black patients' calculated eGFR, making their kidneys appear healthier than they actually were, which delayed transplant referrals and missed CKD diagnoses. The race-free version is more equitable and is what every modern lab now reports. The KDIGO stages: G1 (eGFR over 90) is normal kidney function, G2 (60 to 89) is mildly reduced (often normal for older adults), G3a (45 to 59) and G3b (30 to 44) are moderate CKD where lifestyle and blood pressure control become critical, G4 (15 to 29) is severe and needs nephrology specialist care, G5 (under 15) is kidney failure where dialysis or transplant are typically the options. Honest take: a single low eGFR reading is not a diagnosis. Acute illness, dehydration, recent intense exercise, or a high-protein meal can all temporarily drop the number. Doctors generally want to see two readings 3 months apart before diagnosing CKD. If your number is low, the most important next steps are tight blood pressure control (under 130/80), tight blood sugar control if you're diabetic, avoiding NSAIDs like ibuprofen and diclofenac (which silently damage kidneys), and seeing a nephrologist if you're below 60. CKD progression is often slow and can be meaningfully slowed with treatment — early action genuinely matters.

Pro tips most people learn the hard way

A single eGFR reading is not a diagnosis. Acute illness, dehydration, recent intense exercise, or a high-protein meal can all temporarily drop the number. Doctors generally want two readings 3 months apart before diagnosing CKD. Don't panic over one low number — retest in 8 to 12 weeks under normal conditions first.
The race-free 2021 CKD-EPI formula replaced the older equation that added 21 percent to Black patients' calculated eGFR — a coefficient that delayed transplant referrals and missed CKD diagnoses for years. If your lab is still using the 2009 formula and you're Black, ask them to recalculate with the 2021 version.
If your eGFR is below 60, you should be seeing a nephrologist, not just relying on your GP. The specialist will track progression, adjust medications (some drug doses need reducing as kidney function drops), and plan ahead so you're never caught unprepared. Waiting until you're below 30 to start specialist care is leaving good outcomes on the table.
NSAIDs (ibuprofen, diclofenac, naproxen — sold in Pakistan as Brufen, Voltral, Naproxen) silently damage kidneys, especially in people with reduced function. Common chronic use for headaches and joint pain accelerates CKD progression. If your eGFR is under 90, switch to paracetamol where possible and never take NSAIDs daily without explicit nephrologist approval.
Tight blood pressure control (under 130/80) and tight blood sugar control (HbA1c under 7 for diabetics) are the single most effective interventions for slowing CKD progression. ACE inhibitors and ARBs (medications like ramipril, losartan) specifically protect kidneys — your nephrologist may prescribe these even if your BP looks fine.

?What is the eGFR Calculator (Kidney Function)?

The eGFR (estimated Glomerular Filtration Rate) Calculator estimates kidney function from serum creatinine, age, and sex using the CKD-EPI 2021 formula — the current National Kidney Foundation / American Society of Nephrology recommendation, replacing older race-adjusted equations. Reports eGFR in mL/min/1.73 m² (already body-surface-area normalized) and classifies into KDIGO Chronic Kidney Disease stages G1-G5. Used by every nephrology clinic in the world; an essential check for diabetes, hypertension, and pre-medication safety.

The Formula

CKD-EPI 2021: eGFR = 142 × min(Scr/κ, 1)^α × max(Scr/κ, 1)^−1.2 × 0.9938^age × (1.012 if female). κ=0.9(M)/0.7(F), α=−0.302(M)/−0.241(F). Scr in mg/dL.

The 'race-free' update in 2021 removed the controversial race coefficient that systematically over-estimated kidney function in Black patients (delaying transplant referrals). The new formula uses only creatinine, age, and sex — evidence-based and equitable. eGFR is reported per 1.73 m² (body-surface-area normalized) so values are comparable across body sizes. KDIGO stages: G1 ≥90, G2 60-89, G3a 45-59, G3b 30-44, G4 15-29, G5 <15.

Practical Examples

Healthy 30-year-old male, creatinine 1.0 mg/dL: eGFR ≈ 105 mL/min/1.73 m² (G1, normal).

Healthy 65-year-old female, creatinine 0.9 mg/dL: eGFR ≈ 70 (G2, age-related decline — likely normal).

Diabetic 60-year-old male, creatinine 1.7 mg/dL: eGFR ≈ 47 (G3a, beginning CKD).

Creatinine 2.5 mg/dL in a 50-year-old female: eGFR ≈ 22 (G4, severe — needs nephrology referral).

Creatinine 6.0 mg/dL: eGFR ≈ 9 (G5, kidney failure — dialysis or transplant required).

Frequently Asked Questions

Because creatinine production depends heavily on muscle mass. A 65 kg woman with creatinine 1.0 has substantially worse kidney function than a 90 kg man with the same number — but the raw creatinine doesn't tell you that. eGFR adjusts for age and sex (which serve as rough proxies for muscle mass) to give a fairer comparison across very different bodies.

Popular Conversions

Jump to a ready-made conversion — useful for quick reference and sharing:

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Calculate Body Mass Index against WHO and Asian-population thresholds for men and women using kg or lb, cm or inches, with healthy-range guidance.

BMR Calculator

Estimate Basal Metabolic Rate using the Mifflin-St Jeor equation by sex, age, weight and height — the resting kcal/day baseline for diet planning.

TDEE Calculator

Compute Total Daily Energy Expenditure from BMR and activity multiplier (sedentary to extra active) to set kcal targets for cutting, maintenance, or bulking.

Ideal Weight Calculator

Find your ideal weight range in kg and lb using the Robinson, Miller, Devine and Hamwi formulas alongside the BMI 18.5-24.9 healthy band for men and women.

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Calculate daily water intake in millilitres or litres from body weight and exercise minutes, with hot-climate, pregnancy and breastfeeding adjustments.

Body Fat Calculator

Estimate body fat percentage with the US Navy tape-measure method using neck, waist and hip in cm or inches — a no-cost alternative to DEXA scans for men and women.

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eGFR Calculator (Kidney Function)

Health

Estimate Glomerular Filtration Rate using CKD-EPI 2021 (race-free) for adults. CKD stage classification + KDIGO reference.

Health

eGFR Calculator (Kidney Function)

Generated on May 23, 2026

Serum creatinine

Typical adult: 0.6-1.3 mg/dL (53-115 µmol/L).

Age (years)

Sex

Save / share— download or share to WhatsApp, Facebook & more

Premium Converters

eGFR Result

eGFR 95 mL/min/1.73 m² — G1 — Normal

Generated

5/23/2026

G1 — Normal

95 mL/min/1.73 m²

Normal kidney function (with kidney damage marker for CKD diagnosis).

Kidney function gauge

CKD stage scale (KDIGO)

G1 — Normal≥ 90Normal kidney function (with kidney damage marker for CKD diagnosis).

G2 — Mild60-89Mildly decreased function. Still considered normal for many older adults.

G3a — Mild-moderate45-59Beginning of clinically significant CKD. Adjust some medication doses.

G3b — Moderate-severe30-44More significant decline. See nephrologist; manage cardiovascular risk.

G4 — Severe15-29Severe decline. Prepare for renal replacement therapy (dialysis or transplant).

G5 — Kidney failure0-14Kidney failure. Dialysis or transplant typically needed.

Step-by-step calculation

Formula

CKD-EPI 2021 (race-free): eGFR = 142 × min(Scr/κ, 1)^α × max(Scr/κ, 1)^−1.2 × 0.9938^age × (1.012 if female). κ = 0.9 (M) or 0.7 (F). α = −0.302 (M) or −0.241 (F).

1Serum creatinine: 1.0 mg/dL.
2Age: 45 years, sex: male.
3κ (kappa) = 0.9, α (alpha) = −0.302.
4eGFR = 142 × min(1.000/0.9, 1)^−0.302 × max(1.000/0.9, 1)^−1.2 × 0.9938^45.
5= 94.59 mL/min/1.73 m² → G1 — Normal.
6KDIGO stage definitions: G1 ≥90, G2 60-89, G3a 45-59, G3b 30-44, G4 15-29, G5 <15.

Quick Answer

Estimate Glomerular Filtration Rate using CKD-EPI 2021 (race-free) for adults. CKD stage classification + KDIGO reference.

Overview — eGFR Calculator (Kidney Function)

Health

Formula

CKD-EPI 2021: eGFR = 142 × min(Scr/κ, 1)^α × max(Scr/κ, 1)^−1.2 × 0.9938^age × (1.012 if female). κ=0.9(M)/0.7(F), α=−0.302(M)/−0.241(F). Scr in mg/dL.

By Muhammad Salman SaleemUpdated: May 23, 2026MethodologyFree, no sign-upRuns in your browser — your data stays private

From the editors — what to know before you start

Pro tips most people learn the hard way

A single eGFR reading is not a diagnosis. Acute illness, dehydration, recent intense exercise, or a high-protein meal can all temporarily drop the number. Doctors generally want two readings 3 months apart before diagnosing CKD. Don't panic over one low number — retest in 8 to 12 weeks under normal conditions first.
The race-free 2021 CKD-EPI formula replaced the older equation that added 21 percent to Black patients' calculated eGFR — a coefficient that delayed transplant referrals and missed CKD diagnoses for years. If your lab is still using the 2009 formula and you're Black, ask them to recalculate with the 2021 version.
If your eGFR is below 60, you should be seeing a nephrologist, not just relying on your GP. The specialist will track progression, adjust medications (some drug doses need reducing as kidney function drops), and plan ahead so you're never caught unprepared. Waiting until you're below 30 to start specialist care is leaving good outcomes on the table.
NSAIDs (ibuprofen, diclofenac, naproxen — sold in Pakistan as Brufen, Voltral, Naproxen) silently damage kidneys, especially in people with reduced function. Common chronic use for headaches and joint pain accelerates CKD progression. If your eGFR is under 90, switch to paracetamol where possible and never take NSAIDs daily without explicit nephrologist approval.
Tight blood pressure control (under 130/80) and tight blood sugar control (HbA1c under 7 for diabetics) are the single most effective interventions for slowing CKD progression. ACE inhibitors and ARBs (medications like ramipril, losartan) specifically protect kidneys — your nephrologist may prescribe these even if your BP looks fine.

?What is the eGFR Calculator (Kidney Function)?

The Formula

CKD-EPI 2021: eGFR = 142 × min(Scr/κ, 1)^α × max(Scr/κ, 1)^−1.2 × 0.9938^age × (1.012 if female). κ=0.9(M)/0.7(F), α=−0.302(M)/−0.241(F). Scr in mg/dL.

Practical Examples

Healthy 30-year-old male, creatinine 1.0 mg/dL: eGFR ≈ 105 mL/min/1.73 m² (G1, normal).

Healthy 65-year-old female, creatinine 0.9 mg/dL: eGFR ≈ 70 (G2, age-related decline — likely normal).

Diabetic 60-year-old male, creatinine 1.7 mg/dL: eGFR ≈ 47 (G3a, beginning CKD).

Creatinine 2.5 mg/dL in a 50-year-old female: eGFR ≈ 22 (G4, severe — needs nephrology referral).

Creatinine 6.0 mg/dL: eGFR ≈ 9 (G5, kidney failure — dialysis or transplant required).

Frequently Asked Questions

Popular Conversions

Jump to a ready-made conversion — useful for quick reference and sharing:

Browse all Health

BMI Calculator

Calculate Body Mass Index against WHO and Asian-population thresholds for men and women using kg or lb, cm or inches, with healthy-range guidance.

BMR Calculator

Estimate Basal Metabolic Rate using the Mifflin-St Jeor equation by sex, age, weight and height — the resting kcal/day baseline for diet planning.

TDEE Calculator

Compute Total Daily Energy Expenditure from BMR and activity multiplier (sedentary to extra active) to set kcal targets for cutting, maintenance, or bulking.

Ideal Weight Calculator

Find your ideal weight range in kg and lb using the Robinson, Miller, Devine and Hamwi formulas alongside the BMI 18.5-24.9 healthy band for men and women.

Water Intake Calculator

Calculate daily water intake in millilitres or litres from body weight and exercise minutes, with hot-climate, pregnancy and breastfeeding adjustments.

Body Fat Calculator

Estimate body fat percentage with the US Navy tape-measure method using neck, waist and hip in cm or inches — a no-cost alternative to DEXA scans for men and women.

Macro Calculator

Calculate your daily protein, carbohydrate, and fat targets based on your goals.

Pregnancy Due Date Calculator

Estimate baby's due date using Naegele's rule (LMP + 280 days), adjusted for cycle length, with conception date, trimester boundaries and current week and day.

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See every tool in this category, plus FAQs and category-specific guides.

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eGFR Calculator (Kidney Function) — Glomerular Filtration Rate using CKD-EPI 2021… | Premium Converters

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eGFR Calculator (Kidney Function)

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Kidney function gauge

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Step-by-step calculation

Overview — eGFR Calculator (Kidney Function)

From the editors — what to know before you start

Pro tips most people learn the hard way

?What is the eGFR Calculator (Kidney Function)?

The Formula

Practical Examples

Frequently Asked Questions

Popular Conversions

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eGFR Calculator (Kidney Function)

eGFR Calculator (Kidney Function)

eGFR Result

Kidney function gauge

CKD stage scale (KDIGO)

Step-by-step calculation

Overview — eGFR Calculator (Kidney Function)

From the editors — what to know before you start

Pro tips most people learn the hard way

?What is the eGFR Calculator (Kidney Function)?

The Formula

Practical Examples

Frequently Asked Questions

Popular Conversions

Embed this calculator on your site

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eGFR Calculator (Kidney Function)

eGFR Calculator (Kidney Function)

Kidney function gauge

CKD stage scale (KDIGO)

Step-by-step calculation

Overview — eGFR Calculator (Kidney Function)

From the editors — what to know before you start

Pro tips most people learn the hard way

?What is the eGFR Calculator (Kidney Function)?

The Formula

Practical Examples

Frequently Asked Questions

Why don't we use creatinine alone?

Why was race removed in 2021?

Does eGFR replace 24-hour urine collection?

Below what eGFR is dialysis needed?

Can eGFR be too HIGH?

Popular Conversions

Embed this calculator on your site

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Premium Converters

eGFR Calculator (Kidney Function)

eGFR Calculator (Kidney Function)

Kidney function gauge

CKD stage scale (KDIGO)

Step-by-step calculation

Overview — eGFR Calculator (Kidney Function)

From the editors — what to know before you start

Pro tips most people learn the hard way

?What is the eGFR Calculator (Kidney Function)?

The Formula

Practical Examples

Frequently Asked Questions

Why don't we use creatinine alone?

Why was race removed in 2021?

Does eGFR replace 24-hour urine collection?

Below what eGFR is dialysis needed?

Can eGFR be too HIGH?

Popular Conversions

Embed this calculator on your site

More Health Tools

Browse other categories