Chain-length-dependent termination rate coefficients of the bulk free-radical polymerization of styrene at 80degreesC are determined by combining online polymerization rate measurements (DSC) with living RAFT polymerizations. Full k(t) versus chain-length plots were obtained indicating a high k(t) value for short chains (2 x 10(9) L . mol(-1) . s(-1)) and a weak chain-length dependence between 10 and 100 monomer units, quantified by an exponent of -0.14 in the corresponding power law [k(t)(i,i)] = k(t)(0) . P-b.