Levelheaded

Thesaurus
assured, balanced, calm, collected, commonsense, composed, confident, cool, coolheaded, dispassionate, equable, equanimous, equilibrious, even, even-tempered, logical, philosophical, poised, practical, pragmatic, rational, reasonable, recollected, reposeful, sane, self-assured, self-confident, self-controlled, self-possessed, self-restrained, sensible, serene, sober, sober-minded, sound, together, tranquil, well-balanced