Calculates CrCl via Cockcroft-Gault with body weight adjustment, CKD-EPI 2021 (race-free), and MDRD 4-variable eGFR. Includes CKD staging and drug dosing thresholds.
Patient Parameters
Must be ≥18 yearsEnter a valid age (18–120)
Used for IBW and CKD-EPI coefficients
kgEnter a valid weight (20–300 kg)
cmEnter a valid height (100–230 cm)
mg/dL — normal: M 0.74–1.35, F 0.59–1.04Enter a valid creatinine (0.1–20 mg/dL)
eGFR Results
Cockcroft-Gault
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mL/min
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CKD-EPI 2021
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mL/min/1.73m²
—
MDRD 4-Variable
—
mL/min/1.73m²
—
CKD Stage (based on CKD-EPI 2021)
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—
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CKD Staging Reference
Stage
eGFR (mL/min/1.73m²)
Description
G1
≥90
Normal or High
G2
60–89
Mildly decreased
G3a
45–59
Mildly to moderately decreased
G3b
30–44
Moderately to severely decreased
G4
15–29
Severely decreased
G5
<15
Kidney failure
Drug Dosing Thresholds
eGFR Range
Clinical Guidance
Key Drug Considerations
>60 mL/min
Normal dosing for most drugs
Minimal renal dose adjustments required for most common medications
45–60 mL/min
Caution for some drugs
Metformin: use with caution; some antibiotics require monitoring
30–44 mL/min
Reduce doses
Metformin: use with caution (consider stopping); DOACs dose-reduce; many antibiotics require adjustment
15–30 mL/min
Significant reductions needed
Metformin: STOP; many drugs contraindicated; DOAC adjustments critical; NSAIDs avoid
<15 / Dialysis
Major restrictions; nephrology consult
Most renally-cleared drugs require specialist guidance; dialysis-specific dosing applies
Formulas Used
Cockcroft-Gault:
IBW (Male) = 50 + 2.3 x ((Height_cm / 2.54) - 60)
IBW (Female) = 45.5 + 2.3 x ((Height_cm / 2.54) - 60)
If ABW > 1.3 x IBW => use Adjusted BW = IBW + 0.4 x (ABW - IBW)
Else if ABW < IBW => use ABW
Else use ABW (within normal range)
CrCl = [(140 - Age) x Weight / (72 x SCr)] x (0.85 if female)
CKD-EPI 2021 (race-free):
kappa = 0.7 (female) / 0.9 (male)
alpha = -0.241 (female) / -0.302 (male)
eGFR = 142 x min(SCr/k,1)^alpha x max(SCr/k,1)^(-1.200) x 0.9938^Age x (x1.012 if female)
MDRD 4-Variable:
eGFR = 175 x SCr^(-1.154) x Age^(-0.203) x (x0.742 if female)
Medical Disclaimer
CKD-EPI 2021 is the recommended race-free equation (KDIGO 2024). Cockcroft-Gault is used primarily for drug dosing. MDRD is provided for historical reference and may be less accurate at higher GFR values. Results should be interpreted in clinical context. This calculator does not replace clinical judgment or laboratory reporting.
