An arrangement 5 of acoustic transducers (7a, 7b, 7c, 7d, 9a, 9b, 9c, 9d, 11a, 11b,11c, 11d, 13a, 13b, 13c, 13d) for a flow meter. The flow meter is for measuring the rate at which fluid is flowing. The arrangement includes a respective transducer set (7, 9, 11, 13) for each edge of a notional regular polygon NRP. The transducer sets are associated with a tubular cavity for carrying the fluid. Each of the transducer sets respectively includes two acoustic transducers oriented to define an acoustic path lying in a measurement plane MP7 of the respective set, and another two acoustic transducersoriented to define another acoustic path lying in the measurement plane of the respective set. The transducers sets are positioned so that, in cross-section normal to the tubular cavity, the measurement plane of each respective transducer set is coincident with a respective edge of the notional regular polygon.