What eGFR formula is used in Australian labs?

Australian laboratories use the CKD-EPI 2021 equation (race-free version) as recommended by KHA-CARI and the RCPA. This replaced the MDRD formula and the race-adjusted CKD-EPI 2009 equation.

What is a normal eGFR in Australia?

An eGFR of 60 mL/min/1.73m² or above is generally considered normal. CKD requires eGFR below 60 or evidence of kidney damage persisting for 3 months or more.

When should a GP refer to nephrology?

KDIGO and KHA-CARI recommend referral for: eGFR below 30, rapid decline more than 5 mL/min/year, ACR above 300 mg/mmol, uncertain aetiology, or refractory hypertension with CKD.

CKD-EPI 2021 KHA-CARI / RCPA Clinician tool

eGFR Calculator

Race-free CKD-EPI 2021 — the formula used by Australian laboratories. Instant CKD staging, the KDIGO risk heat map with optional ACR, prescribing flags, and referral guidance.

📋 Sources: CKD-EPI 2021 race-free creatinine equation — Inker LA et al. NEJM 2021;385:1737–1749. KDIGO CKD Guideline 2024 — kdigo.org. KHA-CARI Guidelines — cari.org.au. RCPA eGFR reporting — rcpa.edu.au.
This calculator is for decision-support only. eGFR estimates have limitations in extremes of muscle mass, pregnancy, and acute illness. CKD diagnosis requires two results ≥3 months apart. Always apply clinical judgement and consult current guidelines. Your doctor or healthcare provider knows your history — always follow their personalised advice.

Try a scenario

Serum Creatinine

Age (years)

Biological Sex

Add ACR (albumin:creatinine ratio) Enables full KDIGO 2-axis risk stratification

Urine ACR (mg/mmol) normal <3 mg/mmol

⚗

Enter creatinine, age and sex to calculate

KDIGO Risk Stratification (Heat Map)

● Low ● Moderately increased ● High ● Very high — highlighted cell is your patient.

⚠️ Prescribing considerations at this eGFR

CKD Staging — KDIGO 2024

≥90

Normal or high

Annual if risk factors

60–89

Mildly decreased

Annual

G3a

45–59

Mild–moderately decreased

6-monthly

G3b

30–44

Moderately–severely decreased

3–6 monthly

15–29

Severely decreased

1–3 monthly

<15

Kidney failure

Nephrology

CKD diagnosis requires eGFR <60 or evidence of kidney damage persisting for ≥3 months. A single low eGFR alone is not diagnostic.

What affects eGFR accuracy

💪

Muscle mass — High muscle mass raises creatinine, lowering eGFR without true kidney disease. Low muscle mass (elderly, malnutrition, amputation) gives falsely reassuring eGFR. Consider cystatin C in these patients.

🥩

Dietary meat — A large cooked-meat meal before the test transiently raises creatinine. Advise patients to avoid this on test day.

💊

Drugs that raise creatinine without affecting GFR — trimethoprim, cimetidine, fenofibrate. These inhibit tubular creatinine secretion. Cystatin C or nuclear GFR may be needed for clarity.

🏥

Acute illness / dehydration — Can cause transient pre-renal eGFR drop. Repeat after recovery before diagnosing CKD.

🧬

Cystatin C — More accurate when creatinine is unreliable. Request CKD-EPI creatinine-cystatin C 2021 for borderline or discordant presentations.

Australian labs report eGFR as “>90” when the value is 90 or above. The CKD-EPI formula is less precise at higher values so a specific number is not given. This is a normal result. This calculator matches lab reporting and displays >90 for these results.

KHA-CARI and KDIGO 2024 indications: eGFR <30 (G4–G5), decline >5 mL/min/1.73m² per year or >25% within 12 months, ACR >300 mg/mmol (A3), unexplained haematuria with CKD, suspected genetic cause, refractory hypertension, electrolyte complications, or consideration of kidney replacement therapy. Earlier referral is appropriate for younger patients.

Always use eGFR. A creatinine of 110 µmol/L in a 30-year-old muscular male may correspond to eGFR >90; the same value in a 75-year-old woman may correspond to eGFR ~45. Drug dosing, contrast safety, and CKD staging all require eGFR — not the raw creatinine.

Albumin:creatinine ratio (ACR) in a spot urine sample is the recommended screen for albuminuria. KDIGO categories: A1 (<3 mg/mmol, normal), A2 (3–30 mg/mmol, moderately increased), A3 (>30 mg/mmol, severely increased). Combined with eGFR stage, ACR determines the full KDIGO risk category, which drives monitoring frequency and treatment intensity. Albuminuria is both a CKD diagnostic criterion and an independent cardiovascular risk marker.

Australian labs report creatinine in µmol/L. US labs use mg/dL. Conversion: µmol/L ÷ 88.4 = mg/dL. Use the toggle above the creatinine field to switch. Normal adult creatinine: approximately 60–110 µmol/L (0.7–1.2 mg/dL).

Related tools

⚗️

Creatinine Clearance

Cockcroft-Gault for drug dosing

🫘

CKD Management Reference

KHA action plan, BP targets, SGLT2i, when to refer

🥗

Kidney-Friendly Eating

Potassium & phosphate in foods — a plain reference.

📋

Investigation Frequency

Monitoring intervals by condition

📊

Normal Lab Values

Australian reference ranges

📋 Formula: CKD-EPI Creatinine 2021 (race-free) — Inker LA et al., NEJM 2021;385:1737–1749. Staging & risk: KDIGO 2024 CKD Clinical Practice Guideline. AU implementation: KHA-CARI Guidelines — cari.org.au. RCPA Chemical Pathology Manual — rcpa.edu.au. Decision-support tool only. Use your laboratory’s reported eGFR for clinical decisions.

🫀 Not sure what eGFR means? Read the plain-English eGFR guide — what the number means, CKD stages, and what to ask your GP.

🧪 Pathology reference: eGFR (Estimated glomerular filtration rate) — Pathology Tests Explained (RCPA) ↗