Carboplatin Dose Calculator (Calvert Formula)
Estimate carboplatin dose using: Dose (mg) = Target AUC × (GFR + 25). This tool estimates GFR using Cockcroft-Gault creatinine clearance.
What Is a Carboplatin Calculator?
A carboplatin calculator helps estimate chemotherapy dose based on kidney function and target drug exposure. Unlike many drugs that are dosed only by body surface area, carboplatin is commonly dosed with the Calvert formula, which accounts for renal clearance.
Because carboplatin elimination depends heavily on kidney function, estimating glomerular filtration rate (GFR) or creatinine clearance (CrCl) is central to safe dosing. This calculator combines a target AUC with an estimated renal function value to produce a suggested dose in milligrams.
The Formula Used
Calvert Formula
Dose (mg) = Target AUC × (GFR + 25)
- Target AUC is selected by the oncology regimen.
- GFR is often estimated in clinical workflows (commonly via Cockcroft-Gault CrCl as a practical proxy).
- 25 represents non-renal clearance in the original model.
Renal Function Estimation in This Tool
This page estimates renal function using the Cockcroft-Gault equation:
CrCl (mL/min) = ((140 - age) × weight in kg) / (72 × SCr in mg/dL), multiplied by 0.85 for females.
Different institutions may use different approaches (measured GFR, CKD-EPI conversions, protocol-specific creatinine minimums, or caps). Always follow local protocol.
How to Use This Calculator
- Enter the prescribed target AUC from the treatment protocol.
- Enter patient demographics and labs (age, sex, height, weight, serum creatinine).
- Choose creatinine units correctly (mg/dL or µmol/L).
- Select the weight method for Cockcroft-Gault (ABW, IBW, AdjBW, or Auto).
- Choose whether to cap CrCl at 125 mL/min.
- Click Calculate Dose to view estimated carboplatin dose.
Why Weight Selection Matters
Weight choice can significantly affect estimated CrCl and final carboplatin dose.
- ABW (Actual Body Weight): straightforward but may overestimate renal function in obesity.
- IBW (Ideal Body Weight): may underestimate in some patients.
- AdjBW (Adjusted Body Weight): often used when ABW is substantially above IBW.
- Auto mode in this tool: uses AdjBW when ABW is >120% of IBW; otherwise ABW.
Clinical Notes and Safety Considerations
Use With Caution In:
- Rapidly changing renal function
- Very low muscle mass or cachexia
- Amputations or unusual body composition
- Dialysis-dependent patients
- Pediatric populations (different methods may apply)
Protocol Variability
Oncology regimens differ across institutions. Some centers use a minimum serum creatinine value, some prefer measured GFR, and many cap CrCl for safety. This is why calculated values are a starting point, not a final order.
Example Interpretation
If a patient has an estimated CrCl of 80 mL/min and target AUC is 5, then:
Dose = 5 × (80 + 25) = 525 mg
This value still requires clinician review in context of treatment intent, prior toxicities, platelet trends, and institutional standards.
Frequently Asked Questions
Is this calculator enough to prescribe carboplatin?
No. It is an estimation tool and must be reviewed by licensed oncology professionals.
Should CrCl always be capped at 125 mL/min?
Many protocols do cap at 125 mL/min, but practice can differ. Follow your local chemotherapy policy and protocol.
Can I use this for any cancer regimen?
The math is general, but regimen-specific AUC targets and eligibility rules are not. Always check the regimen protocol.
Bottom Line
A carboplatin calculator is useful for quickly applying the Calvert formula and improving dosing consistency. Still, safe chemotherapy dosing is a multidisciplinary process. Use this tool to support—not replace—clinical judgment, pharmacy verification, and institutional protocol.