Dose by BSA (mg/m²)
Converts BSA-based dosing (mg/m²) to actual dose using patient height and weight
Calculator
Why use it
Standard method for chemotherapy dose calculation. Accounts for body size variability. Required for most oncology regimens. Prevents dosing errors in BSA-based medications.
About
Calculates actual drug dose from a BSA-based prescription (mg/m²). Uses the Mosteller formula (BSA = √(height × weight / 3600)) to compute BSA, then multiplies by the prescribed dose per m². Essential for chemotherapy dosing, some pediatric medications, and other BSA-based protocols.
When to use
- Chemotherapy dose calculation
- Any medication dosed by BSA (mg/m²)
- Pediatric dosing when BSA-based dosing is specified
Formula
Pearls & pitfalls
- Some institutions cap BSA at 2.0 m² for dosing — check institutional policy.
- Obese patients: consider ideal or adjusted BSA; discuss with oncologist.
- Mosteller formula (√(H×W/3600)) and Du Bois formula agree within ~3% for most patients.
- ALWAYS have chemotherapy doses independently verified by two providers.
- Round doses to practical amounts based on available vial sizes.
Next steps
Verify BSA and calculated dose with a second provider. Check for dose-capping rules (e.g., BSA cap at 2.0 m² for some agents). Adjust for organ function (renal, hepatic). Round to practical dose based on available vial sizes.
Evidence
BSA-based dosing is the standard for most chemotherapy regimens since the 1950s. While imperfect (does not account for pharmacokinetics), it remains the universal standard in oncology practice.
References
- Mosteller RD. Simplified calculation of body surface area. N Engl J Med. 1987;317(17):1098. — link