eGFR Calculator — Estimated Glomerular Filtration Rate
Enter your serum creatinine level, age, and biological sex to calculate your estimated glomerular filtration rate (eGFR) using the CKD-EPI 2021 equation and identify your CKD stage.
mg/dL
år
Biological sex
CKD stage G1 — Normal or high (≥90)
- 1
Creatinine ratio (Scr ÷ κ)
1 ÷ 0,9 = 1,1111κ = 0.9 for male - 2
Low-range term min(ratio, 1)^α
1^(-0,302) = 1 - 3
High-range term max(ratio, 1)^(−1.2)
1,1111^(−1.2) = 0,881234 - 4
Age decay factor 0.9938^Age
0.9938^45 = 0,755883 - 5
eGFR (CKD-EPI 2021)
142 × 1 × 0,8812 × 0,7559 = 94,6
Hvordan fungerer denne lommeregner?
eGFR estimates kidney filtration rate from serum creatinine, age, and sex using the CKD-EPI 2021 equation. Normal is ≥90 mL/min/1.73 m². Values below 60 for ≥3 months indicate CKD. The formula: 142 × min(Scr/κ,1)^α × max(Scr/κ,1)^(−1.2) × 0.9938^Age × sex factor, where κ is 0.7 (female) or 0.9 (male).
Formel
How this is calculated
The glomerular filtration rate (GFR) measures how much blood the kidneys filter per minute per standard body surface area (1.73 m²). Because directly measuring GFR requires infusing a marker substance, clinical practice uses creatinine — a muscle waste product excreted almost entirely by filtration — to estimate it. The CKD-EPI 2021 equation, published in the New England Journal of Medicine and adopted by KDIGO 2022, is the current recommended race-free formula for adults 18 and older.
The formula divides serum creatinine by a sex-specific constant (κ: 0.7 for female, 0.9 for male) and applies different exponents depending on whether the ratio is above or below 1. Age is included as an exponential term because GFR naturally declines about 1 mL/min per year after age 40. The sex multiplier of 1.012 for females reflects lower average muscle mass and creatinine production in the reference population.
The KDIGO staging system classifies results into six stages: G1 (≥90, normal), G2 (60–89, mildly reduced), G3a (45–59), G3b (30–44), G4 (15–29, severely reduced), and G5 (<15, kidney failure). A single eGFR value should always be interpreted alongside urine albumin-to-creatinine ratio (ACR) and clinical context — transient illness, dehydration, or certain medications can acutely lower eGFR without reflecting chronic kidney disease.
Ofte stillede spørgsmål
An eGFR of 90 mL/min/1.73 m² or above is classified as normal or high (CKD stage G1) when no other signs of kidney damage are present. Values below 60 for more than three months indicate chronic kidney disease (CKD). eGFR naturally declines with age — a value of 65 in an 80-year-old may not indicate disease requiring intervention.
The CKD-EPI 2021 equation uses sex at birth because creatinine production correlates with muscle mass, which differs systematically between male and female reference populations used to derive the formula. The 2021 version removed race as a variable — unlike the earlier 2009 equation — following evidence that race-based adjustments systematically disadvantaged Black patients.
Dehydration, high red-meat intake before the blood draw, intense exercise, and certain drugs (trimethoprim, cimetidine, creatine supplements) can raise serum creatinine without reflecting true kidney damage. Very low muscle mass — in elderly, malnourished, or limb-amputated patients — can give a falsely reassuring (high) eGFR. Always repeat an abnormal result before concluding CKD is present.
Også kendt som
TG we-Calculate Editorial Team. (2026). eGFR Calculator — Estimated Glomerular Filtration Rate [Online calculator]. TG we-Calculate. https://we-calculate.com/da/calculator/efg-calculator
TG we-Calculate Editorial Team. "eGFR Calculator — Estimated Glomerular Filtration Rate." TG we-Calculate. 2026. https://we-calculate.com/da/calculator/efg-calculator.
TG we-Calculate Editorial Team, "eGFR Calculator — Estimated Glomerular Filtration Rate," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/da/calculator/efg-calculator
@misc{wecalculate_efg_calculator, title = {eGFR Calculator — Estimated Glomerular Filtration Rate}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/da/calculator/efg-calculator}}, year = {2026}, note = {TG we-Calculate} }
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