Jiri D. performs an estimate:
With a rising prices of utilities like gas and power and winter still being in progress it might be good to check your usage from time to time. With electricity and TOU meters, it is easy, retailer does that for you and you can check your consumption and projected bill at any time with a granularity of 30 minute interval (sometimes even less).
With gas (and water) it is trickier, those are being read manually every 2 – 3 months so you may be up for a surprise when the bill arrives.
I had a co-worker who tracked this stuff in meticulous detail over a period of several years, to the point where he knew exactly how much propane to buy in August (when prices are lowest) to get through winter with minimum waste.