The portable hand cycle is a user-stabilized device for upper body exercise. The portable hand cycle is held in place using the weight of a user, holding a platform against the seat of a chair, couch, or other surface. In a sitting position, a riser connected to the seat extends up and away from the user. The riser is optionally of an adjustable length in order to fit users of different sizes. The riser ends with a sleeve that encloses an axle, the center of which is placed at chest-level with respect to the user. The crank is connected to a pair of crank-arms that in turn terminate with grips. To operate, the user extends her arms and holds the grips in her hands. Her rotation of her hands moves the grips, which in turn rotates the crank-arms, finally rotating the axle.