Enter patient details to estimate creatinine clearance quickly. See renal stage and adjustment tier instantly. Always confirm doses with pharmacist and prescribing information current.
| Date | Primary estimate | Category | Tier | Inputs (age/sex/wt/SCr) |
|---|---|---|---|---|
| No logged results yet. | ||||
| Case | Age | Sex | Ht (cm) | Wt (kg) | SCr | Primary method | Typical outcome |
|---|---|---|---|---|---|---|---|
| A | 55 | Male | 175 | 82 | 1.0 mg/dL | CrCl | Often normal–mild impairment |
| B | 72 | Female | 160 | 60 | 1.4 mg/dL | CrCl | Often moderate impairment |
| C | 68 | Male | 178 | 105 | 2.0 mg/dL | CrCl | Often severe impairment |
| D | 45 | Female | 165 | 70 | 120 µmol/L | eGFR | Often mild–moderate impairment |
Renal impairment changes drug exposure because many agents rely on filtration and tubular secretion. This calculator uses adult inputs to estimate kidney function and then maps the estimate to practical adjustment tiers. The category cut points mirror common staging thresholds: ≥90, 60–89, 30–59, 15–29, and <15. Using these boundaries helps standardize conversations between prescribers, nursing, and pharmacy while you confirm the exact label instructions for the medication in use.
For many medications, guidance is written for creatinine clearance from Cockcroft–Gault, not eGFR. The equation uses (140 − age), body weight, and serum creatinine, divided by 72, with a female multiplier of 0.85. If creatinine is provided in µmol/L, the value is converted to mg/dL by dividing by 88.4. The calculator can also compute CKD‑EPI 2021 eGFR to support clinical context and documentation.
After calculation, the result is summarized as a renal category and an adjustment tier. A “standard dosing” tier generally corresponds to ≥90, while 60–89 signals caution and closer monitoring. Values of 30–59 commonly require a lower dose or longer interval, and 15–29 often require major reductions or alternative agents. Results below 15 prompt specialist or label‑required guidance and dialysis‑specific considerations, because timing and modality can change clearance.
Weight selection can materially change Cockcroft–Gault. The tool offers actual body weight (ABW), ideal body weight (IBW), and adjusted body weight (AdjBW). IBW is calculated from height using the 50/45.5 kg base plus 2.3 kg per inch over 5 feet, and AdjBW uses IBW + 0.4 × (ABW − IBW). A practical rule is to consider AdjBW when ABW exceeds 120% of IBW. BMI and BSA outputs add context for dosing and monitoring.
Use the output to plan safe prescribing steps. Confirm renal function trends, consider acute kidney injury, and document the method used (CrCl vs eGFR) with units. Pair the adjustment tier with drug‑specific monitoring such as trough levels, electrolytes, glucose, or QT interval when relevant. Record the timestamped summary, the chosen weight basis, and any safety flags (low muscle mass, frailty, dialysis). This supports auditability and helps teams re‑evaluate dosing when labs change. Recheck within 24–48 hours after major shifts occur.
Use the method required by the drug’s prescribing information. Many dose-adjustment tables are written for Cockcroft–Gault creatinine clearance, while eGFR supports CKD staging and documentation. When in doubt, confirm with a pharmacist or local protocol.
ABW is common for non-obese adults. If actual weight is much higher than IBW, AdjBW can reduce overestimation; a practical trigger is ABW >120% of IBW. IBW may be used for very lean patients, per policy.
Be cautious. Serum creatinine may lag behind rapid changes, so calculated clearance can be misleading. Review urine output, trends, hemodynamics, and repeat labs. Use drug-specific guidance and consider specialist input for high-risk medicines.
No. eGFR is reported as mL/min/1.73m² and reflects a standardized body surface area, while Cockcroft–Gault estimates mL/min using body weight. Values can diverge, especially at extremes of size or age.
If creatinine is entered in µmol/L, the calculator converts to mg/dL by dividing by 88.4 before applying formulas. Double-check that the lab unit matches your entry to avoid large errors.
It provides a renal category and a general adjustment tier, not medication-specific dosing. Final dose, interval, and monitoring depend on the drug, indication, route, dialysis status, and patient factors. Always consult authoritative references.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.