A distinct cultivar of Chrysanthemum plant named `Yocalcutta`, characterized by its uniform and upright plant habit; freely branching growth habit; strong stems; dark green and glossy foliage; uniform flowering response; early flowering, eight-week response time; very large decorative-type inflorescences that are about 10.9 cm in diameter; dark soft orange ray florets with yellow apices; and excellent postproduction longevity with plants maintaining good substance and color for at least three weeks in an interior environment.