The utility model relates to the technical field of caps, and discloses an adjustable cap which comprises a peaked cap, an adjusting belt is fixedly connected in the peaked cap, one end of the adjusting belt is fixedly connected with a frame, and a locking
assembly is arranged in the frame. The locking
assembly comprises a
locking plate, one side of the
locking plate is rotationally connected into the frame, an adjusting groove is formed in the frame, the adjusting belt is arranged in the adjusting groove in a penetrating mode, an open groove is formed in the frame, a locking groove is formed in the frame, and a toothed plate is fixedly connected to the bottom of the
locking plate. According to the adjustable cap, the position of the frame on the outer wall of the adjusting belt is adjusted, the adjusting belt is shortened, then the
head circumference of the peaked cap is adjusted, only the locking plate and the frame need to be buckled during locking, the clamping block in the locking plate and the locking groove are embedded for locking, the effect of rapidly adjusting the
head circumference of the cap is achieved, and the problem that the
head circumference of the cap cannot be adjusted rapidly during traditional buckle adjustment is solved. Therefore, the convenience of the adjustable hat is improved.