Chemotherapy Dose Calculator

Most chemotherapy protocols dose by body surface area (BSA) in m², not by weight alone, because drug clearance correlates better with BSA across the wide range of adult body sizes than with weight or a fixed dose would. This calculator uses the Mosteller formula -- published by Mosteller in the New England Journal of Medicine in 1987 -- sqrt(height in cm times weight in kg, divided by 3600), one of several published BSA formulas (others include DuBois-DuBois and Haycock), chosen here for its simplicity and that it produces results very close to the more complex alternatives for typical adult heights and weights. The protocol dose per m² is the single value that scales the per-cycle dose directly; body height and weight matter only through how they combine into BSA, and at typical adult dimensions the resulting BSA usually falls comfortably below 2.0 m², so the optional BSA cap has no effect unless a patient's calculated BSA actually exceeds that threshold.

That 2.0 m² cap reflects a common institutional practice: capping the BSA used for dosing, rather than dosing the full uncapped BSA, in larger patients, since the relationship between BSA and drug clearance becomes less reliable at BSA extremes and uncapped dosing risks excess toxicity without a proportional efficacy gain. Number of planned cycles only multiplies the per-cycle dose into a cumulative total for the whole course; it does not change the dose calculated for any single cycle. This calculator does not itself apply renal or hepatic dose adjustments -- the reduction percentage field is a manual override the prescriber enters based on the specific protocol's dose-modification table, and any calculated dose still requires independent verification against the written order before administration.