Chemo Dose Calculator

Calculate estimated dosing from body metrics and protocol. Review formulas, export results, and compare scenarios safely. Verify with your oncology team always.

Safety note: This tool is for education and double-checking only. Dosing must be verified by a qualified clinician using current protocols, labs, and clinical context.

Calculator

Choose the protocol’s dosing style.
From regimen / protocol documentation.
Some regimens cap total dose.
Rounding applies in exports only.
Typically selected per protocol.
Preferred when available.
Shown in exports as a reminder.
Reset

Example Data Table

Scenario Height (cm) Weight (kg) BSA (m²) Protocol input Estimated dose (mg)
BSA example 170 70 1.8181 75 mg/m² 136.36
AUC example 165 60 1.6583 AUC 5, CrCl 70 475.00
Cap example 180 95 2.1519 100 mg/m², cap 200 mg 200.00
Examples are illustrative and not clinical recommendations.

Formula Used

  • Body Surface Area (Mosteller): BSA (m²) = √((Height(cm) × Weight(kg)) / 3600)
  • BSA-based dosing: Dose (mg) = BSA (m²) × Prescribed (mg/m²)
  • Cockcroft–Gault estimate (optional): CrCl (mL/min) = ((140 − Age) × Weight) / (72 × SCr) × SexFactor
  • Calvert (carboplatin): Dose (mg) = Target AUC × (GFR/CrCl + 25)
Clinical practice varies for weight selection, unit conventions, and capping rules. Always follow local protocol and pharmacy guidance.

How to Use This Calculator

  1. Select the dosing method that matches your regimen.
  2. Enter height and weight, then enter protocol inputs.
  3. For AUC dosing, prefer measured GFR/CrCl when available.
  4. Press Calculate to show results above the form.
  5. Export CSV/PDF for documentation and peer review.
  6. Confirm final dose with oncology pharmacy and protocol.

Clinical Context and Guidance

Dose individualization basics

Chemotherapy dosing often begins with an evidence based protocol target, then adjusts for patient size, renal clearance, and documented toxicity. Body surface area models correlate imperfectly with exposure, yet remain common for many cytotoxics. Accurate height and weight entry helps reduce arithmetic errors and supports consistent verification across teams.

Body surface area method

The Mosteller approach estimates surface area from height and weight, then multiplies by a regimen specific mg per m² value. This produces a starting dose in milligrams. Some institutions apply caps to limit extreme doses or standardize vial usage. Any cap must follow the prescribing protocol and pharmacy policy.

Renal function and AUC

For carboplatin, exposure is commonly targeted using area under the curve dosing. The Calvert formula combines the target AUC with an estimated or measured GFR or creatinine clearance plus a constant of 25. When measured clearance is available, it is generally preferred over estimates, especially at extremes of age or muscle mass.

Rounding and preparation

Rounding practices vary and may reflect vial sizes, stability limits, and dose banding programs. Document the chosen rounding rule and apply it consistently. When changing rounding, separate calculation from compounding decisions, and record both the calculated dose and the prepared dose to maintain traceability for audits and safety checks.

Verification and monitoring

Before administration, verify patient identifiers, protocol cycle and day, dose reductions, organ function labs, and recent toxicities. Monitor for infusion reactions, myelosuppression, renal changes, and cumulative dose limits where applicable. Use this calculator as a transparent worksheet to support double checks, not as a substitute for clinical judgment.

Common modifiers include prior grade three or four toxicities, hepatic impairment, neuropathy risk, and concurrent radiotherapy. Record planned reductions as percentages and the clinical reason, so future cycles remain consistent. If laboratory values change between ordering and administration, recalculate using the most recent verified results. When serum creatinine is unusually low, some centers apply minimum values to avoid overestimating clearance; follow local policy. Always confirm units, especially mg per m² versus mg per kg, and keep a second checker independent. Capture infusion volume, diluent, and rate limits in notes to support compounding accuracy and administration safety.

FAQs

1) Does BSA dosing fit every drug?

No. Many regimens still use BSA, but some use fixed doses, weight based dosing, or exposure targets. Always follow the protocol for the specific agent.

2) Should I use measured GFR when available?

Yes. A measured clearance can better reflect renal function than estimates in some patients. Enter it when provided by your lab or nephrology service.

3) Why is there a +25 term in the Calvert method?

The constant approximates nonrenal clearance for carboplatin. It is part of the published formula and should not be modified unless your protocol explicitly states otherwise.

4) What weight should be used for clearance estimates?

Policies differ. Some use actual, ideal, or adjusted weight depending on body habitus. Use the approach specified by your institution and regimen documentation.

5) Can I apply dose caps automatically?

Caps should only be applied when the protocol or local policy requires them. If a cap is used, document the cap value and the uncapped calculation.

6) Is this output safe to prescribe from?

No. This tool supports education and double checking. Final prescribing must consider labs, toxicity history, comorbidities, interactions, and current clinical guidance.

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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.