We present a neutron guide which is curved in the shape of a logarithmic spiral. Simulations and calculations for such a spiral guide are presented and the potential use of the guide for a reflectometer is investigated and compared to the conventional circularly curved guide geometry. We concentrate on the specific case of a beamport at the SINQ source. For this application, the spiral guide shows a 30% increased flux on the region of interest while at the same time reducing background scattering due to beam converging.