Calculating my gas bill (approx)

paultw5

Where do i start,

Can someone please point me in the direction of trying to estimate my gas bill. I've searched the forum (got even more confused), searched the web without success, and am now at my last resort (MSE).

In laymans terms:

My last 1/4.

Previous reading, 6717. new reading 7283. Units used = 566.

price = 3.099 p for the first 1143 kwh, then 2.262 p for the rest.....

566 units, what are they ? are they the kwh ? Have i used 566 kwh in the last quarter. if so do i times 566 x 3.099 p for my bill (is it that simple?).

Appologies if i'm being really stupid here, but i seem to be loosing the plot :cool:

Thanks for any response...Cheers Paul......

PS i'm with Scottish Power if that means anything.

Cardew

You have used 566 units, but that is not kWh.

It depends if you have a Metric or Imperial Meter. If you look at the meter it will have something like 'cu ft' for Imperial or M3 for Metric. The newer meters are metric.

If it is Metric the amount of kWh you have used if approx 11.3 x 566 = 6,396kWh -the exact formula is on your bill and depends on calorific value.

If your meter is Imperial you have used 2.86 times more kWh.

To calculate your bill the first 1,143 are at the higher rate and the rest at the lower rate.

oldwiring

Yes units have to be converted to kWh. From my experience gas bills in the small print give the formulla for conversion. This is an example from my latest bill
Units 106 x
Correction factor 1.022640 =
Adjusted units 108.39

As my meter is imperial not metric the adjusted units are multiplies by 2.83
to give cubic metres used
= 306.77
then cubic metres are multiplied by calorific value, in this case 39.0411 and finally divided by 3.6 to give kWh.

As you can see it is a quite compicted sum but the final kWh figure comes out at 3326.84.

Just to muddy matters the correction factor and calorific value alter slightly from time to time.

To simplify I would suggest that you take the units and for an imperial meter multipy by 31.4 and for a metric meter 11.1.

paultw5

Thanks to the pair of you.

The meter is M3 (metric) .

Units used is 566

my correction factor is 1.022640

My Cal value is 39.0

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So 566 x 1.022640 (correction factor) = 578.81424.

578.81424 (cubic metres of gas) x 39.0 (correction factor) = 22573.755.

Then i divide that total by 3.6, so 22573.755 divided by 3.6 = 6270.4875.

---

So my total kWh is 6270.4875, rounded up to 6271.

So for the first 1143 kWh i am paying 2.933p (inc vat)= 3352.419 or £33.53 (rounded up)
and for the rest (5128) i am paying 1.958p (inc vat)= 10040.624 or £100.41 (rounded up)

So my bill will be £133.94.

Would anyone who understands this calculation tell me if i am correct, or care to comment otherwise.

Again thanks in advance Paul

espresso

Yes that looks correct to me. Easy when you know how!

:hello:

paultw5

Learn something new everyday on MSE...

Thanks again people.....

Cardew

paultw5 wrote:

So for the first 1143 kWh i am paying 2.933p (inc vat)= 3352.419 or £33.53 (rounded up)
and for the rest (5128) i am paying 1.958p (inc vat)= 10040.624 or £100.41 (rounded up)

So my bill will be £133.94.

Would anyone who understands this calculation tell me if i am correct, or care to comment otherwise.

Again thanks in advance Paul

Your first post gave different prices for each unit.

price = 3.099 p for the first 1143 kwh, then 2.262 p for the rest

Are you sure your last post is using current prices?

gotnobread

"So my total kWh is 6270.4875, rounded up to 6271."

Spot on, apart from you always round down the number of kWh (you can only be billed for energy you have actually used). So you're out by a whole 1kWh!

Also, although it doesn't make any difference to this particular bill, you always truncate the number of m3 to 1 decimal place - in other words, 578.81424m3 would be put through the rest of the calculation as 578.8.

Suppliers must calculate in this way to comply with the Calculation of Thermal Energy regulations.

Cheers,
Gotnobread

paultw5

Cardew, you are right.

I'm billed on line, but have last years prices in front of me, so it was easier to do the calculation on the thread that way.

Obviously my next task is to go online and get my current prices and do the calculation.

Then for the Electric, which i hope is a whole lot easier. ??

---

gotnobread, round down instead of up, and away i go. :beer:

Cheers Paul........

oldwiring

espresso wrote:

Yes that looks correct to me. Easy when you know how!

:hello:

I agree the calcs too,

Morseman

paultw5 wrote:

I'm billed on line, but have last years prices in front of me, so it was easier to do the calculation on the thread that way.

Obviously my next task is to go online and get my current prices and do the calculation.

Then for the Electric, which i hope is a whole lot easier. ??

---

Most gas bills are now a set rate, if you are on a "X at one rate and Y at another" you may want to check that you are on the best deal. If you have never changed from a British Gas account, you may find a better deal.

The electricity one should be easier, as the meter reads kWh and not Therms, BTU, metres cubed or cubic feet and there's no correction for calorific value either!

However, you may find there's two readings "Low" for night time use and "Normal" for daytime. The "Low" rate is cheaper than "Normal" rate.

If you have an older 'dial' meter, you need to be careful how you read it. Each dial goes round a different way to the previous one, as they are powered by gears and one goes 'clockwise' and the next 'anticlockwise' and so on. If the previous dial hasn't reached zero, the next one is read on the number before... All very confusing and full time meter readers get it wrong!