Body surface area Fujimoto calculator

Missing height or weight, or non-positive values, are rejected with invalid_input so incomplete forms never invent a surface area.

How to call the API and what comes back

Send a JSON body with two required finite positive numbers: height (aliases height_cm, h, stature, ht) and weight (aliases weight_kg, w, mass, wt). Optional height_unit defaults to cm and accepts cm, m, or in; optional weight_unit defaults to kg and accepts kg or lb. After conversion, height must stay within three hundred centimetres and weight within five hundred kilograms so intermediate powers remain finite on the Worker and in the browser. On success the response echoes rounded height and weight as submitted, height_unit and weight_unit as normalized labels, height_cm and weight_kg after conversion, bsa and bsa_m2 as the same rounded square-metre value, unit as the string m2, formula as the Fujimoto expression string, formula_name as Fujimoto, message as a short English summary, and steps as an ordered array of substitution lines showing the weight term, the height term, and the final product. Failed validation—missing required fields, non-finite numbers, non-positive height or weight, unsupported unit labels, or values outside absolute limits after conversion—returns invalid_input and is never charged. Pricing is a flat $0.002 per successful request with unit item and zero marginal unit price. When you only have one of the two anthropometrics, do not invent the other: leave the field empty so the API surfaces the missing-field error instead of a fabricated BSA.

Practical tips, limits, and related searches

Keep anthropometrics inside the published absolute range after conversion so the powered intermediate cannot overflow into a non-finite BSA that the solver must reject. Prefer sending numbers rather than pre-formatted strings when you control the client; string numbers are accepted only when they match a strict finite numeric pattern. When teaching, pair examples: one hundred seventy centimetres and seventy kilograms yields a typical adult Fujimoto value near one point seven six m²; one hundred sixty centimetres and fifty-five kilograms yields a smaller adult value; deliberate zero weight, negative height, or an omitted weight field demonstrates the hard invalid_input path; and a five-foot-seven adult entered as sixty-seven inches with one hundred fifty-four pounds shows unit conversion into the same centimetre-kilogram pipeline. This landing targets people searching for a body surface area Fujimoto calculator, Fujimoto formula BSA, or BSA from height and weight online under the Fujimoto model; it is not a Mosteller or Du Bois calculator, not a BMI tool, and not a clinical dosing system that applies milligrams per square metre to a drug. Prefer this capability when a protocol, paper, or homework set names Fujimoto; if your source asks for Mosteller or Du Bois, use those dedicated capabilities instead so the formula_name and numeric result match the named model. Failed tasks that return invalid_input do not consume prepaid balance, which keeps exploratory scripts cheap when learners deliberately omit weight or set height to zero. Round-trip checks are easy: recompute zero point zero zero eight eight eight three times weight_kg to the zero point four four four times height_cm to the zero point six six three by hand and confirm it equals the published bsa within the same twelve-decimal rounding, and confirm that changing only the sign of an input or dropping a required field flips the response from success to invalid_input.