How to roughly predict gas bill in advance?

[Cryogenic]

I have a diaphragm gas meter which is measured in meters cubed (m3). It has 8 digits,the last 3 of which are in red, example:

99920678

Firstly, what is a unit exactly, the 6 or 7 or 8, or the 0 or 2 in this example?

Secondly, the calculation varies from area to area, but assuming this calculation:

-Multiply by the temperature and pressure figure (1.02264).
-Multiply by colorific value (39.2)
-Divide by 3.6 to get the number of kilowatt hours (kWh)

Assuming 5 units used at 5p per kWh, I get £2.78. Does that sound about right?

I tried doing a search on Google but can only find info on reading a digital meter or converting cubic feet to metres cubed. Thanks.

 

[misterPK]

Take a look at an old bill, that might help.

PK!

 

[ste_bla]

99920 m3

Edit : http://www.npower.com/web/In_business/Customer_services/Meterreadings/How_To_Read_Your_Gas

£2.78 for how long and whats it used for?

 

[Pookie Bear]

You appear to have a metric meter, the first five digits of those eight are your reading.

Assuming your CV value is correct (it's difficult for a consumer to get the exact figure without contacting your supplier as they are updated daily), then your calculation is accurate. A higher CV will make a difference of a few percent (off the top of my head, it shouldn't be higher than 43 unless you live in Stornoway).

In this case, 5 metric units are equal to 55 kwh, at 5p/kwh = 275p. Don't forget VAT at 5% (assuming this is domestic use), that's £2.88. Don't forget standing charges (if any) and the fact that you may be on a multi-tiered pricing arrangement.

I remember back in 1995 when I first started in the industry, a metric unit was around 18p (rough estimate we used back then)... and now it's closer to 55p.

 

[Cryogenic]

Thanks for the advice chaps

 

[Azagoth]

I know exactly, to the penny, just how much my gas bill is going to be and to this day I have never got it wrong once!