British gas - how to calculate cost of heating

pumen

I moved into a new flat this week and the flat has both gas and electricity. My previous flat only had electricity, so I am not familiar how gas usage is calculated and is paid for. I understand that the cost of unit is in kwh, but the meter is in f3. The existing supplier is the British Gas and according to their website, the cost of unit is 4.11p for my area in London, including VAT. So, how can I estimate the usage in kwh?- when I moved in, the meter reading was 7718.55, now it is 7719.65. The gas is used for heating and hot water. So, I basically used 1.1 ft3 - how much money does this cost? I just want to understand the cost of all this before I start using heating

Nada666

One imperial meter unit is about 32 kWh - multiply the meter difference by 32.

Your 1.1 units will cost about £1.45.

[Deleted User]

Ok, if your meter is an imperial one, it's reading in hundreds of cubic feet, so you first multiply by 2.832 to convert into cubic metres.

Next you multiply by the volume conversion factor. This is to compensate for the difference in temperature and pressure between your house and the laboratory conditions where the gas is measured. You should find it marked on your bill somewhere, mine's about 1.02 so it doesn't actually make much difference.

Now multiply by the calorific value of the gas, it's also marked on the bill somewhere, and it's usually around 39MJ/m^3.

Lastly, divide by 3.6, because there are 3.6MJ/kWh.

so your 1.1 units will be around:

1.1*2.832*39*1.02/3.6 = 34kWh

At 4.11p/kWh that comes to a grand total of £1.41

D_M_E

jack_pot's reply is correct, but I suggest you use Nada666's estimate and put a further 20% in a savings account to allow for a little credit to build up.

Also, don't forget to add a further charge for delivery and everything else which could be up to a further 30p or more a day.

You also need to look for cheaper deals as 4.11p seems expensive compared to around 2.5p or less for other companies. Work out your estimated usage per day - now it's not costing much but will go up, so I suggest you use your current usage as the expected usage for the next 9 months then add on about 30% of your current daily usage for the remaining 3 months for the gas and just use your current daily use for electricity for the whole year -

Example - if your current daily gas use is 100 cubic feet, then use 100x270 days = 27000 + 30 x 90 = 2700 total 29700 cubic meters and use the calculation given by jack_pott to work out the equivalent kwh JUST AN EXAMPLE put your own figures in to give a reasonable estimate to put in comparison websites.

Nada666

No, do not use Jack Pott's calculation, that is a waste of time. My figure is an approximation, not an estimate.

If wanted, wait for the bill and use the figures on it for the fancy calculation.

modsandmockers

Pumen - it is good that you are keeping a record of your meter readings. Submit meter readings to your supplier at monthly intervals, and if ever you receive a bill which has used 'estimated' readings, then protest immediately and supply up-to-date actual readings. Here is a link which might help you to convert your gas meter readings into kWhours - http://www.energylinx.co.uk/gas_meter_conversion.html - when you receive your bills, they will show you the precise calculations. Have you contacted British Gas and given them your details? Do you know for sure that your start meter readings have been put onto BG's computer system? It's likely that you will be, or have been, put onto BG's most expensive 'standard variable tariff' so shop around - BG may well have a cheaper tariff which you can switch to immediately, but it might have an early exit fee. It might be worth sticking with BG for a year (but not on their standard variable tariff) until you have a good idea of your annual consumption levels.

Your energy costs will consist of a separate daily charge for each fuel and a different price per kWh for each fuel - make sure that you know the prices for the tariff which you have selected and check your quarterly bills carefully (the prices will be listed on the Tariff Information Label which your supplier should provide automatically). Your monthly direct debit payment is not a reliable indicator of your actual costs, and it is easy to accumulate a massive debit or credit balance on the account if you don't monitor it properly.

pumen

Thank you. I am not sure whether this is an imperial meter or not.

pumen

jack_pott wrote: »

Ok, if your meter is an imperial one, it's reading in hundreds of cubic feet, so you first multiply by 2.832 to convert into cubic metres.

Next you multiply by the volume conversion factor. This is to compensate for the difference in temperature and pressure between your house and the laboratory conditions where the gas is measured. You should find it marked on your bill somewhere, mine's about 1.02 so it doesn't actually make much difference.

Now multiply by the calorific value of the gas, it's also marked on the bill somewhere, and it's usually around 39MJ/m^3.

Lastly, divide by 3.6, because there are 3.6MJ/kWh.

so your 1.1 units will be around:

1.1*2.832*39*1.02/3.6 = 34kWh

At 4.11p/kWh that comes to a grand total of £1.41

Thank you. The formula is very helpful, but how do I know if the meter is imperial or not?

pumen

D_M_E wrote: »

jack_pot's reply is correct, but I suggest you use Nada666's estimate and put a further 20% in a savings account to allow for a little credit to build up.

Also, don't forget to add a further charge for delivery and everything else which could be up to a further 30p or more a day.

You also need to look for cheaper deals as 4.11p seems expensive compared to around 2.5p or less for other companies. Work out your estimated usage per day - now it's not costing much but will go up, so I suggest you use your current usage as the expected usage for the next 9 months then add on about 30% of your current daily usage for the remaining 3 months for the gas and just use your current daily use for electricity for the whole year -

Example - if your current daily gas use is 100 cubic feet, then use 100x270 days = 27000 + 30 x 90 = 2700 total 29700 cubic meters and use the calculation given by jack_pott to work out the equivalent kwh JUST AN EXAMPLE put your own figures in to give a reasonable estimate to put in comparison websites.

Thank you. I also believe 4.11p is expensive, but I can't find a tariff of 2.5p as you suggest. The lowest one i could find on the uswitch is EON uswitch for 1 yr fixed at 10.67p for electric and 3.13p for gas with a standing charge of 21.90p per day

victor2

pumen wrote: »

Thank you. The formula is very helpful, but how do I know if the meter is imperial or not?

Look at the meter. It will have ft3 or m3 on it somewhere near the reading display. ft3 means it's imperial and m3 metric. Also verify that your supplier has the same type of meter on their records. As you won't have a bill yet, you may have to phone them and ask.
Don't worry too much about the accurate calculation for units to kWh, a close approximation can be achieved by multyiplying ft3 by 32 and m3 by 11. The reason you multiply ft3 by more than m3 (when cubic metres are bigger than cubic feet) is because imperial meters measure hundreds of cubic feet, which are often referred to as HCF.

pumen

victor2 wrote: »

Look at the meter. It will have ft3 or m3 on it somewhere near the reading display. ft3 means it's imperial and m3 metric. Also verify that your supplier has the same type of meter on their records. As you won't have a bill yet, you may have to phone them and ask.
Don't worry too much about the accurate calculation for units to kWh, a close approximation can be achieved by multyiplying ft3 by 32 and m3 by 11. The reason you multiply ft3 by more than m3 (when cubic metres are bigger than cubic feet) is because imperial meters measure hundreds of cubic feet, which are often referred to as HCF.

Thanks. Just looked- it is Schlumberger R5 meter with f3, so imperial