Design of a pressure sensor workable from megapascal (MPa) to gigapascal (GPa) pressure range is proposed on a two dimensional triangular/hexagonal lattice silicon (Si) photonic crystal (PhC) arrangement. In order to ensure high resolution sensing over this wide pressure range, a hexagonal shaped ring of hexagonal unit cells and two micromachined silicon cantilever tips are considered on the photonic crystal arrangement. The concept of using micromachined cantilever tip in a PhC arrangement for optical sensing of pressure is novel. Moreover, use of hexagonal ring with hexagonal unit cells make the structure more sensitivity than other types of ring arrangement. It is shown that the two silicon cantilever tips can be used to detect applied pressure from 1 MPa to 10 MPa with resolution of 1 MPa and 10 MPa to 100 MPa with a resolution of 10 MPa, respectively. Detection of applied pressure from 20 MPa to 10 GPa with the resolution of 20 MPa can be done using the hexagonal ring of hexagonal unit cells. The entire design is done using the MPB (MIT Photonic Bands) and MEEP (MIT Electromagnetic Equation Propagation) simulators freely available from MIT, USA. © 2018 Elsevier B.V.