A tape cassette includes: a cassette casing; and a tape roll that is a roll of a tape extending in a lengthwise direction and a widthwise direction. The tape includes: a subject surface exposed in a thickness direction; and a first image provided on the subject surface and indicating first information. The tape roll has: a first end portion located at an inner portion of the tape roll in a radial direction of the tape roll; and a second end portion located at an outer portion of the tape roll in the radial direction. The first information relates to an amount of a portion of the tape which is located on a first-end-portion-side of a reference position in the lengthwise direction. The reference position is located on the first-end-portion-side of the first image in the lengthwise direction on the tape at a particular distance from the first image.