GFR calculator (eGFR, CKD-EPI 2021)

eGFR from serum creatinine (mg/dL or µmol/L), age and sex by the race-free CKD-EPI 2021 equation, with optional cystatin C and the KDIGO G1–G5 stage.

Mis à jour Exemples vérifiés : 8

Standardized (IDMS-traceable) value from a blood test.
years
The CKD-EPI equations are validated for adults aged 18 and over.
mg/L
Adds the 2021 creatinine–cystatin C and 2012 cystatin C equations.
Plus d’options
Adds the KDIGO albuminuria category and heat-map risk.
Essayer
eGFR (creatinine, CKD-EPI 2021)
mL/min/1.73 m²
eGFR (creatinine, CKD-EPI 2021): 92 mL/min/1.73 m²
Nombre entier ; Au plus proche, égalités en s’éloignant de zéro
GFR category (KDIGO 2024)
G1: normal or high
Creatinine in the other unit
88µmol/L
eGFR assumes stable creatinine. It is unreliable in acute kidney injury, pregnancy, amputation, very high or low muscle mass, and after creatine supplements or a large meat meal.

For a man aged 50 with creatinine 1.00 mg/dL, the 2021 CKD-EPI equation gives an eGFR of 92 mL/min/1.73 m². That is KDIGO category G1: normal or high.

KDIGO GFR categories

G5G4G3bG3aG2G101530456090130eGFRcr 92

eGFR by creatinine for a man aged 50

0501001234Creatinine (mg/dL)eGFR (mL/min/1.73 m²)You: 9260: G3a starts
KDIGO 2024 risk by GFR and albuminuria category Lignes : 6
GFR categoryDFG estiméA1 (ACR < 30 mg/g)A2 (30–300)A3 (> 300)
G1 (you)≥ 90LowModerateHigh
G260–89LowModerateHigh
G3a45–59ModerateHighVery high
G3b30–44HighVery highVery high
G415–29Very highVery highVery high
G5< 15Very highVery highVery high
Comment le calcul est effectué S
  1. Constants for men

    κ=0.9,α=−0.302,Scrκ=10.9=1.1111\kappa = 0.9,\quad \alpha = -0.302,\quad \frac{S_{cr}}{\kappa} = \frac{1}{0.9} = 1.1111

    The ratio is 1 or more, so the min term equals 1 and the max term uses −1.200.

  2. CKD-EPI 2021 creatinine equation

    142×1.1111−1.200×0.993850=91.69142 \times 1.1111^{-1.200} \times 0.9938^{50} = 91.69

    KDIGO 2024 asks for eGFR to be reported as a whole number in mL/min/1.73 m².

  3. KDIGO GFR category

    Creatinine eGFR reported as 92 → G1: normal or high. Bands: G1 ≥ 90, G2 60–89, G3a 45–59, G3b 30–44, G4 15–29, G5 < 15.

À propos de GFR calculator (eGFR, CKD-EPI 2021)

Estimated glomerular filtration rate (eGFR) is the volume of blood plasma the kidneys filter each minute, scaled to a body surface area of 1.73 m². It is calculated from serum creatinine, age and sex with the 2021 CKD-EPI equation, which dropped the race coefficient of the 2009 version; the National Kidney Foundation and the American Society of Nephrology recommend it for adults in the US. With a cystatin C result the 2021 creatinine–cystatin C equation is also computed, and KDIGO 2024 grades the kidneys on that combined value when it is available.

Clinicians use eGFR to stage chronic kidney disease and to adjust drug doses. A 50-year-old man with a creatinine of 1.0 mg/dL (88 µmol/L) has an eGFR of 92, category G1. An eGFR below 60 for more than 3 months is chronic kidney disease, category G3a or worse.

The equations assume creatinine is stable. They read wrong in acute kidney injury, pregnancy, very high or low muscle mass, and after a meat-heavy meal or creatine supplements.

Exemples détaillés

Man, 50 years, creatinine 1.0 mg/dL

Serum creatinine
1.0
Creatinine unit
mg/dL
Âge
50 years
Sex (for the formula)
Male
eGFR (creatinine, CKD-EPI 2021)
92 mL/min/1.73 m²
GFR category (KDIGO 2024)
G1: normal or high
Creatinine in the other unit
88 µmol/L
Creatinine in the other unit
sans objet

Source de vérification : Python 3.8 decimal: 142 × (1.0/0.9)^−1.200 × 0.9938^50 = 91.691 (NKF 2021 CKD-EPI creatinine equation); 1.0 × 88.4 = 88.40 µmol/L

Woman, 60 years, creatinine 0.8 mg/dL

Serum creatinine
0.8
Creatinine unit
mg/dL
Âge
60 years
Sex (for the formula)
Female
eGFR (creatinine, CKD-EPI 2021)
84 mL/min/1.73 m²
GFR category (KDIGO 2024)
G2: mildly decreased

Source de vérification : Python 3.8 decimal: 142 × (0.8/0.7)^−1.200 × 0.9938^60 × 1.012 = 84.298

Man, 70 years, creatinine 177 µmol/L

Serum creatinine
177
Creatinine unit
µmol/L
Âge
70 years
Sex (for the formula)
Male
eGFR (creatinine, CKD-EPI 2021)
35 mL/min/1.73 m²
GFR category (KDIGO 2024)
G3b: moderately to severely decreased
Creatinine in the other unit
2.00 mg/dL
Creatinine in the other unit
sans objet

Source de vérification : Python 3.8 decimal: 177 / 88.4 = 2.00226 mg/dL; 142 × (2.00226/0.9)^−1.200 × 0.9938^70 = 35.195

Woman, 45 years, creatinine 0.6 mg/dL, cystatin C 0.9 mg/L

Serum creatinine
0.6
Creatinine unit
mg/dL
Âge
45 years
Sex (for the formula)
Female
Serum cystatin C (optional)
0.9 mg/L
eGFR (creatinine, CKD-EPI 2021)
113 mL/min/1.73 m²
eGFR (creatinine–cystatin C, 2021)
103 mL/min/1.73 m²
eGFR (cystatin C only, 2012)
89 mL/min/1.73 m²
GFR category (KDIGO 2024)
G1: normal or high

Source de vérification : Python 3.8 decimal: eGFRcr = 142 × (0.6/0.7)^−0.241 × 0.9938^45 × 1.012 = 112.735; eGFRcr-cys = 135 × (0.6/0.7)^−0.219 × (0.9/0.8)^−0.778 × 0.9961^45 × 0.963 = 102.910; eGFRcys = 133 × (0.9/0.8)^−1.328 × 0.996^45 × 0.932 = 88.513

Questions

What is a normal eGFR?

90 mL/min/1.73 m² or higher is KDIGO category G1, normal or high, and 60 to 89 is G2, mildly decreased. Neither counts as chronic kidney disease unless there is also kidney damage, such as albumin in the urine, lasting at least 3 months. The equation lowers eGFR by 0.62 % for each year of age, so the same creatinine of 1.0 mg/dL gives a man 92 at age 50 and 81 at age 70.

What eGFR indicates kidney disease?

An eGFR below 60 mL/min/1.73 m² that lasts more than 3 months meets the KDIGO 2024 definition of chronic kidney disease on its own. KDIGO grades it G3a (45–59), G3b (30–44), G4 (15–29) and G5, kidney failure (below 15). A single low reading is not a diagnosis, because acute illness, dehydration or a recent large meat meal can lower eGFR temporarily; KDIGO asks for repeat testing to confirm.

Why was race removed from the eGFR equation?

The 2009 CKD-EPI equation multiplied eGFR by 1.159 for Black patients, a coefficient based on race as a social category. A joint National Kidney Foundation and American Society of Nephrology task force recommended in 2021 that US labs switch to the refitted 2021 equation, which uses creatinine, age and sex only. KDIGO 2024 practice point 1.2.4.2 says race should not be used to compute eGFR.

When should cystatin C be used to estimate GFR?

When creatinine is likely to mislead. KDIGO 2024 Table 8 lists eating disorders, bodybuilding, above-knee amputation, spinal cord injury, vegetarian or high-protein diets and creatine supplements, among others. KDIGO recommends that when cystatin C is available the GFR category be taken from the combined creatinine–cystatin C equation, which is closer to measured GFR than either marker alone. A large gap between eGFRcr and eGFRcys is itself a signal that one of them is off.

How do you convert creatinine from µmol/L to mg/dL?

Divide by 88.4, the factor in the KDIGO 2024 conversion table; it is 10,000 divided by the molar mass of creatinine, 113.12 g/mol. A result of 88 µmol/L is 1.00 mg/dL and 150 µmol/L is 1.70 mg/dL. KDIGO asks labs to report creatinine to the nearest whole number in µmol/L and to two decimals in mg/dL.

Quelle est la précision de « GFR calculator (eGFR, CKD-EPI 2021) » ?

La précision dépend de vos données et des hypothèses de la méthode. Le calcul décimal utilise 50 chiffres significatifs, mais les estimations, méthodes numériques et données sources peuvent être moins précises ; l’arrondi affiché ne supprime pas ces limites. Exemples résolus vérifiés à partir de sources indépendantes : 8. Par exemple, « Man, 50 years, creatinine 1.0 mg/dL » est vérifié à l’aide de Python 3.8 decimal: 142 × (1.0/0.9)^−1.200 × 0.9938^50 = 91.691 (NKF 2021 CKD-EPI creatinine equation); 1.0 × 88.4 = 88.40 µmol/L.

D’où vient cette méthode ?

Inker LA et al. New creatinine- and cystatin C–based equations to estimate GFR without race. N Engl J Med 2021;385:1737–1749; National Kidney Foundation — CKD-EPI creatinine equation (2021); National Kidney Foundation — CKD-EPI creatinine–cystatin C equation (2021); National Kidney Foundation — CKD-EPI cystatin C equation (2012); KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney Int 2024;105(4S):S117–S314; Delgado C et al. A unifying approach for GFR estimation: recommendations of the NKF-ASN Task Force. Am J Kidney Dis 2022;79:268–288.

À propos de ce calculateur

eGFRcr=142×min⁡ ⁣(Scrκ,1)α×max⁡ ⁣(Scrκ,1)−1.200×0.9938age×1.012 [female]\text{eGFR}_{cr} = 142 \times \min\!\left(\tfrac{S_{cr}}{\kappa},1\right)^{\alpha} \times \max\!\left(\tfrac{S_{cr}}{\kappa},1\right)^{-1.200} \times 0.9938^{\text{age}} \times 1.012\ [\text{female}]

Sources

  1. Inker LA et al. New creatinine- and cystatin C–based equations to estimate GFR without race. N Engl J Med 2021;385:1737–1749
  2. National Kidney Foundation — CKD-EPI creatinine equation (2021)
  3. National Kidney Foundation — CKD-EPI creatinine–cystatin C equation (2021)
  4. National Kidney Foundation — CKD-EPI cystatin C equation (2012)
  5. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney Int 2024;105(4S):S117–S314
  6. Delgado C et al. A unifying approach for GFR estimation: recommendations of the NKF-ASN Task Force. Am J Kidney Dis 2022;79:268–288

À titre informatif uniquement, sans avis médical. Ces formules décrivent des populations, pas votre situation personnelle ; consultez un professionnel de santé avant d’agir sur un résultat.

Vérifié avec les références

Ce calculateur comprend 8 exemples résolus dont les réponses proviennent de sources indépendantes. Ils font partie de la suite de tests et peuvent aussi être exécutés ici.

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