This paper uses neutron emission spectrometry (NES), with the spectrometer TOFOR, to estimate the deuterium–tritium (DT) equivalent fusion yields of deuterium-only (DD) pulses at the tokamak JET. A method for making DT predictions using parameters determined from the neutron energy spectrum is described and this method is compared to corresponding estimations done with the modeling codes JESTORR and TRANSP, as well as with results from the 1997 JET DT campaign. The method has been applied to a large number of JET DD pulses conducted after the installation of the ITER-like wall (ILW), and the results have been used to assess the prospects for the upcoming DT campaign (DTE2).DT predictions made by NES produces similar estimations as JESTORR and TRANSP, and the fusion power from studied DT pulses fall in line with the estimated power of similar DD discharges.Extrapolating the recent JET pulses to estimate what the fusion yields would be in DTE2, results indicate that reaching over 10 MW is achievable and that the highest performing ILW pulses to date could approach the desired fusion power of 15 MW.