How much does it cost to run your gas fireplace a night?

Find the tag on the fireplace unit and note the Input rating, then divide that # by 1000 and the answer is the # of cubic feet of gas the burner burns in one hour. Or watch your gas meter for 60 seconds and note the cubic feet used and multiply that times 60 and again you have your cubic feet per hour #, use this method if you dont see a tag. Be sure no other gas appliances in the home are operating while you are reading the meter. Then look at your gas bill and see what a cubic foot of gas costs you and multiply that by cubic feet per hour it uses times the # of hours you run it per night and you have your answer.