You could measure the wattage input to your welder and factor that into the equation but I think you would need to be welding for ages for it to make any real effect in your leccy.If you look you'll find wire consumption tables, electrode stub loss corrections etc in some of the google hits. Doubt you'll find anything on leccy units as there's waaaaaay too many variables- inverter versus transformer with and without power factor correction for example are gonna make a difference both idling and in use
Yeah and welders use plenty of other power tools too. As Danny said it's one of the many costs of running a workshop. Tally 'em all up and you can work out how much it costs just to open the doors per week, day, hour etcYou could measure the wattage input to your welder and factor that into the equation but I think you would need to be welding for ages for it to make any real effect in your leccy.