An image forming apparatus includes an image carrier that carries a toner image formed of toner, a transfer belt, a primary transfer unit that transfers the toner image from the image carrier to the transfer belt, and a secondary transfer unit that transfers the toner image from the transfer belt to a recording medium. A contact pressure P of the primary transfer unit, a thickness T of the transfer belt, and an average roundness R of the toner satisfy expression 1, and the thickness T of the transfer belt satisfies expression 2, a Young's modulus of the transfer belt being 2,500 MPa or more and 5,000 MPa or less, 1.5T-40.ltoreq.P.ltoreq.1.5T+Aexpression 1 40.ltoreq.T.ltoreq.200expression 2 where P is in g/cm.sup.2, T is in .mu.m, and A=2,000R-1,800.