BSA Dose Adjustment Calculator

BSA Dose Adjustment Calculator for Reference Tools. The displayed used area explains the dose actually calculated. A protocol cap and a dose-maximum warning are different operations. A value above the entered maximum requires resolving the order, not substituting the maximum as a new dose.

For shared guidance on choosing a tool and documenting results, read the clinical calculator workflow.

How this calculator works

This workflow explicitly uses Mosteller: BSA = square root of height in cm x weight in kg / 3600. Multiply the unrounded area by the prescribed mg/m2. Only an explicitly selected protocol cap changes the area used for dosing; both uncapped and used areas are reported. The entered maximum dose is a check, not an automatic dose reduction.

When to use this calculator

Check a protocol-specified Mosteller dose after the drug, dosing weight, treatment day and cap policy are established. It is not a generic way to scale an adult fixed dose to a child or to compensate automatically for obesity, renal dysfunction or toxicity.

Inputs used

  • Drug protocol, dosing weight, BSA method, cap policy and prescribed mg/m2 checked
  • Protocol dosing weight (kg)
  • Height (cm)
  • Prescribed dose (mg/m2 per administration)
  • Protocol BSA cap
  • Prescribed BSA cap (m2)
  • Verified maximum dose per administration (mg)

Clinical interpretation

The displayed used area explains the dose actually calculated. A protocol cap and a dose-maximum warning are different operations. A value above the entered maximum requires resolving the order, not substituting the maximum as a new dose.

Worked example

Fictional protocol check: 80 kg and 180 cm give square root of 4 = 2 m2. At 50 mg/m2 the uncapped dose is 100 mg. An explicitly prescribed 1.8-m2 cap changes the used area to 1.8 and the dose to 90 mg. The example entered 120-mg single-dose maximum does not alter either calculation.

Limitations and safety notes

Mosteller is an estimated surface area, not measured drug clearance. This calculator does not implement Du Bois, Haycock, dose banding, organ-function adjustments, toxicity reductions or a universal BSA cap. Check the applicable protocol and independently verify the preparation before administration.

Frequently asked questions

Does a calculated result authorize administration?

No. It checks the entered arithmetic only. The patient-specific order, product, preparation, timing, monitoring and clinical appropriateness need separate verification.

What exactly does this workflow leave to the treating team?

Mosteller is an estimated surface area, not measured drug clearance. This calculator does not implement Du Bois, Haycock, dose banding, organ-function adjustments, toxicity reductions or a universal BSA cap. Check the applicable protocol and independently verify the preparation before administration.

References

  • Mosteller 1987 primary publication identity; publisher abstract page has no full formula extract. https://www.nejm.org/doi/abs/10.1056/NEJM198710223171717
  • Cancer Institute NSW calculator explicitly supplies Mosteller cm/kg/3600 equation; no protocol or dosing cap is inferred. https://www.eviq.org.au/clinical-resources/eviq-calculators/3198-body-surface-area-calculator

Editorial review and citation methodology

Maintained by the Quick Medical Calculator Editorial Team. Content record date: September 9, 2026. A content date is not evidence of independent clinical review. Individual clinical sign-off is not recorded on this page.

  • Prefer original validation studies for scoring systems and prediction tools.
  • Use current specialty society guidance, transplant allocation policy, public health guidance, or regulator resources when they govern clinical use.
  • Include limitations and safety notes when a calculator is population-specific, context-dependent, or unsuitable as a standalone decision tool.

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