A top quark mass measurement is performed using 35.9fb-1 of LHC proton-proton collision data collected with the CMS detector at s=13TeV . The measurement uses the tt¯ all-jets final state. A kinematic fit is performed to reconstruct the decay of the tt¯ system and suppress the multijet background. Using the ideogram method, the top quark mass ( mt ) is determined, simultaneously constraining an additional jet energy scale factor ( JSF ). The resulting value of mt=172.34±0.20(stat+JSF)±0.70(syst)GeV is in good agreement with previous measurements. In addition, a combined measurement that uses the tt¯ lepton+jets and all-jets final states is presented, using the same mass extraction method, and provides an mt measurement of 172.26±0.07(stat+JSF)±0.61(syst)GeV . This is the first combined mt extraction from the lepton+jets and all-jets channels through a single likelihood function.