How much gas am I using?

On days when I'm not at work which really isn't very often, I run this Woodstock Gas Franklin non-stop in my basement. I sleep on the couch down here, etc. I'm used to my Hearthstone at the office where I generally keep it 76 degrees in my workspace. Now, I am so spoiled by that wood heat, I run this Franklin gas to create a similar environment in my basement. Question is, if we run this thing on average 4 hours a day, how much is the damage going to be natural gas wise? It's 70 something percent efficient and our furnace is 92 percent. However, the furnace doesn't give any radiant heat and as soon as it cycles off the basement gets chilly.

As an added item, only had the thing running for 1 month, so I haven't seen a gas bill.

I run my gas stove 18 hours a day and furnace only 6 hours at night. My gas stove runs full max. Dec. to March never shuts off, only at night. in and 100 year old brick house + gas cook stove and gas water heater. I just got my Natural gas bill for 33 days $126.05 Stove is 22,500 BTU input. Been doing this for 4 years now b vent gas heating stove and furnace. I save about 1/3 on gas bill. Lo temp +5F hight temp-30F deg Besides the dog like the gas stove better.

That's reassuring

http://www.woodstove.com/cottage-franklin

22,000 BTU max, although I have it dialed down some. runs on natural gas. vented vertically and then 90 degree bend straight out the wall.

Nice math formula. I like it. I'll remember that...thanks for the information.