Is not that comparing apples to oranges?
Mcf (cubic feet) is a measurement of volume (only way the meter can read) and is fixed...while a Therm is a measurment of heat content and is a variable, depending on hydrocarbon makeup.
If I got this correct, the math gets a little messy???
It all comes down to BTU averages. On average one cubic foot of NG has 1,025 BTU's.
1 Mcf = 1,000 cubic feet
1,000 cubic feet x 1,025 BTU's per cubic foot = 1,025,000 BTU's
1 therm = 100,000 BTU's
1,025,000 (one Mcf) / 100,000 (one Therm) = 10.25 (on average)http://www.eia.gov/tools/faqs/faq.cfm?id=45&t=8