  We present new features of the FeynRules and MadGraph5/aMC@NLO programs for
the automatic computation of decay widths that consistently include channels of
arbitrary final-state multiplicity. The implementations are generic enough so
that they can be used in the framework of any quantum field theory, possibly
including higher-dimensional operators. We extend at the same time the
conventions of the Universal FeynRules Output (or UFO) format to include decay
tables and information on the total widths. We finally provide a set of
representative examples of the usage of the new functions of the different
codes in the framework of the Standard Model, the Higgs Effective Field Theory,
the Strongly Interacting Light Higgs model and the Minimal Supersymmetric
Standard Model and compare the results to available literature and programs for
validation purposes.
