The absolute time of growth of a floating tree-ring series is determined by computer, by first fitting a curve to the 14C ages of tree-ring dated wood and then by matching the 14C ages of the floating tree-ring series to that curve. The results obtained by this matching procedure are given here for five floating European oak chronologies for which 14C dates have been published previously by Suess (1978). Three of these five floating series have been linked together dendrochronologically. There now remain three floating series covering a 4000-year time span from 4820 BC to 830 BC. Their 14C dates, matched by computer to the bristlecone pine chronology, provide a possibility of obtaining precise ages of oak wood series from Neolithic sites in Switzerland and South Germany by dendrochronologically cross-dating with the calibrated master chronologies.