Abstract:The global properties of the final states produced in hadronic interactions of protons at centre-of-mass energies of future hadron colliders (such as FCC-hh at CERN, and SppC in China), are studied. The predictions of various Monte Carlo (MC) event generators used in collider physics (pythia 6, pythia 8, and phojet) and in ultrahighenergy cosmic-rays studies (epos, and qgsjet) are compared. Despite their different underlying modeling of hadronic interactions, their predictions for proton-proton (p-p) collisions at √ s = 100 TeV are quite similar. The average of all MC predictions (except phojet) for the different observables are: (i) p-p inelastic cross sections σ inel = 105 ± 2 mb; (ii) total charged multiplicity N ch = 150 ± 20; (iii) charged particle pseudorapidity density at midrapidity dN ch /dη| η=0 = 9.6 ± 0.2; (iv) energy density at midrapidity dE/dη| η=0 = 13.6 ± 1.5 GeV, and dE/dη| η=5 = 670 ± 70 GeV at the edge of the central region; and (v) average transverse momenta at midrapidities p T = 0.76 ± 0.07 GeV/c. At midrapidity, epos and qgsjet-ii predict larger per-event multiplicity probabilities at very low (N ch < 3) and very high (N ch > 100) particle multiplicities, whereas pythia 6 and 8 feature higher yields in the intermediate region N ch ≈ 30-80. These results provide useful information for the estimation of the detector occupancies and energy deposits from pileup collisions at the expected large FCC-hh/SppC luminosities.