We present a pressure sensor based on the piezoresistive effect of graphene. The sensor is a 100?nm thick, 280??m wide square silicon nitride membrane with graphene meander patterns located on the maximum strain area. The multilayer, polycrystalline graphene was obtained by chemical vapor deposition. Strain in graphene was generated by applying differential pressure across the membrane. Finite element simulation was used to analyze the strain distribution. By performing electromechanical measurements, we obtained a gauge factor of ?1.6 for graphene and a dynamic range from 0?mbar to 700?mbar for the pressure sensor.