I'm using an electric heater to warm up my bedroom while keeping the
temperature in the rest of the house much lower, heated by the furnace.

Is it possible to calculate how much it costs me to run the heater based on
the wattage-- perhaps per hour of continuous use? Thought there might be
some way of knowing how the use of the heater translates to my electric
meter aside from turning off every bit of electricity in the house and
running the heater for an hour (which I'm tempted to do )

Thanks