1. A method of determining geometry of a deformed pipe or conduit or wellbore, the method comprising: receiving measurement data indicative of a plurality of radii of the pipe or conduit collected using a measuring device centred in the pipe at two or more points a known distance from the measurement point but not at the measurement point itself; selecting a deformation type and/or deformation model; processing the measurement data to determine one or more geometrical properties of the pipe or conduit, the geometrical properties being indicative of, or associated with, one or more deformations, shapes or profiles of at least part of the pipe, conduit or wellbore; and guiding and/or constraining at least a part of the processing of the measurement data using the selected deformation type or model and/or fitting the selected deformation model to the measurement data.