An indexing tape for determining respiratory tidal volume settings of a ventilator for a human patient. The tape includes an elongate body, a reference element of the tape body configured for positioning at a first end of the patient, a series of length-indicating elements of the tape body spaced from the reference element and configured so that an aligned one at a second end of the patient indicates the patient's height, and a plurality of ventilator-setting elements of the tape body correlated to the length-indicating elements and including the tidal volumes. A method of determining ventilator settings includes positioning the tape along the patient with the reference element adjacent the patient first end and with one of the length-indicating elements adjacent and aligned with the patient second end, and reading the respective ventilator-setting element corresponding to the aligned length-indicating element to identify an appropriate tidal-volume setting for the ventilator.