An accelerometer caliper while drilling arrangement comprising a drill bit having an axis of rotation and a gauge region, a caliper tool body, a first accelerometer mounted upon the caliper tool body and arranged to measure acceleration in a first direction, and a second accelerometer mounted upon the caliper tool body and arranged to measure acceleration in a second direction orthogonal to the first direction, wherein the caliper tool body and the drill bit are coupled to one another in such a manner that the first and second accelerometers are mounted in a known relationship to the drill bit.